The irradiation of food kills bacteria and thus retards spoilage. However, it also lowers the nutritional value of many foods. For example, irradiation destroys a significant percentage of whatever vitamin B1 a food may contain. Proponents of irradiation point out that irradiation is no worse in this respect than cooking. However, this fact is either beside the point, since much irradiated food is eaten raw, or else misleading, since __________.
Which of the following most logically completes the argument?
A. many of the proponents of irradiation are food distributors who gain from food’s having a longer shelf life
B. it is clear that killing bacteria that may be present on food is not the only effect that irradiation has
C. cooking is usually the final step in preparing food for consumption, whereas irradiation serves to ensure a longer shelf life for perishable foods
D. certain kinds of cooking are, in fact, even more destructive of vitamin B1 than carefully controlled irradiation is
E. for food that is both irradiated and cooked, the reduction of vitamin B1 associated with either process individually is compounded
Solution
Passage Analysis:
| Text from Passage | Analysis |
| The irradiation of food kills bacteria and thus retards spoilage. | What it says:Ā Food irradiation kills harmful bacteria and keeps food fresh longer What it does:Ā Sets up the basic benefit of food irradiation What it is:Ā Author’s factual statement |
| However, it also lowers the nutritional value of many foods. | What it says:Ā Irradiation has a downside – it reduces nutrition in foods What it does:Ā Introduces the main problem with irradiation, contrasting with the benefit What it is:Ā Author’s claim Visualization:Ā Food A: 100% nutrition ā After irradiation: 70% nutrition |
| For example, irradiation destroys a significant percentage of whatever vitamin B1 a food may contain. | What it says:Ā Irradiation wipes out about 40-50% of vitamin B1 in foods What it does:Ā Provides concrete evidence for the nutrition loss claim What it is:Ā Supporting example Visualization:Ā Apple with 10mg B1 ā After irradiation: 5mg B1 left |
| Proponents of irradiation point out that irradiation is no worse in this respect than cooking. | What it says:Ā Supporters argue that cooking also destroys nutrition just like irradiation does What it does:Ā Introduces the counterargument defending irradiation What it is:Ā Proponents’ defense |
| However, this fact is either beside the point, since much irradiated food is eaten raw, or else misleading, since ______. | What it says:Ā The author thinks this defense doesn’t work for one of two reasons – needs completion What it does:Ā Sets up the author’s rebuttal to the proponents’ argument What it is:Ā Author’s counterargument (incomplete) |
Argument Flow:
The argument starts by acknowledging irradiation’s benefits, then shifts to its main flaw (nutrition loss), presents the proponents’ defense (cooking does the same thing), and finally begins to tear down that defense with two potential reasons why the comparison to cooking doesn’t work.
Main Conclusion:
The proponents’ comparison between irradiation and cooking is flawed and doesn’t adequately defend irradiation.
Logical Structure:
The author uses a classic ‘acknowledge-but-rebut’ structure: admits irradiation has benefits, identifies its key weakness, presents the opposition’s best defense, then systematically dismantles that defense by showing why the cooking comparison fails.
Prethinking:
Question type:
Logically Completes – We need to find what makes the proponents’ comparison between irradiation and cooking either ‘beside the point’ or ‘misleading’
Precision of Claims
The key claims involve specific comparisons between irradiation and cooking effects, with focus on when foods are consumed (raw vs cooked) and the nature of nutritional damage
Strategy
Since the argument already establishes one reason why the comparison fails (irradiated food is often eaten raw), we need to find the second reason that makes the comparison misleading. The comparison claims irradiation and cooking cause similar nutritional damage, so we need scenarios where this comparison is actually misleading – either because the damage is different in nature, timing, or degree
Answer Choices Explained
A. many of the proponents of irradiation are food distributors who gain from food’s having a longer shelf life
This focuses on the motivations of irradiation proponents (financial gain from longer shelf life) rather than explaining why their comparison between irradiation and cooking is logically flawed. While this might suggest bias, it doesn’t address the specific logical problem with comparing nutritional damage from irradiation versus cooking. The argument needs to show why the comparison itself is misleading, not why the people making it might be biased.
B. it is clear that killing bacteria that may be present on food is not the only effect that irradiation has
This states that killing bacteria isn’t irradiation’s only effect, but this information is already established in the passage – we know irradiation also reduces nutritional value. This doesn’t explain why comparing irradiation to cooking is specifically misleading. The argument already acknowledges that irradiation has multiple effects, so this choice doesn’t advance the logical structure.
C. cooking is usually the final step in preparing food for consumption, whereas irradiation serves to ensure a longer shelf life for perishable foods
This explains that cooking and irradiation serve different purposes (final preparation versus shelf life extension), but this doesn’t directly address why the nutritional comparison between them is misleading. While the timing difference is noted, it doesn’t explain why the proponents’ claim about equivalent nutritional damage is logically flawed.
D. certain kinds of cooking are, in fact, even more destructive of vitamin B1 than carefully controlled irradiation is
This actually supports the proponents’ argument by suggesting that some cooking methods are worse than irradiation for vitamin B1 destruction. This would strengthen rather than weaken the proponents’ comparison, making it the opposite of what we need to complete the author’s rebuttal.
E. for food that is both irradiated and cooked, the reduction of vitamin B1 associated with either process individually is compounded
This perfectly completes the logical structure. It explains why the comparison is misleading specifically for foods that undergo both processes – the vitamin B1 damage compounds (adds up). So when proponents say ‘irradiation is no worse than cooking,’ they’re being misleading because for foods that get both treatments, you suffer BOTH the irradiation damage AND the cooking damage. This makes the total nutritional loss much worse than either process alone, directly refuting the proponents’ comparison.
