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In this article, we’ll look at the solution to this GMAT sentence correction question: Starfish, with anywhere from five to eight arms, have a strong regenerative ability, and if one arm is lost it quickly replaces it, sometimes by the animal overcompensating and growing an extra one or two.

We have analyzed the 5 answer choices and arrived at the correct choice through 3 steps:

1. Meaning analysis
2. Error analysis
3. Answer choice analysis

General information on this question

• Difficulty level – High
• 52% of people got this question correct
• The average time taken to correctly answer this question – 1:34

Let’s look at the question and answer choices

Starfish, with anywhere from five to eight arms, have a strong regenerative ability, and if one arm is lost it quickly replaces it, sometimes by the animal overcompensating and growing an extra one or two.

(A) one arm is lost it quickly replaces it, sometimes by the animal overcompensating and
(B) one arm is lost it is quickly replaced, with the animal sometimes overcompensating and
(C) they lose one arm they quickly replace it, sometimes by the animal overcompensating,
(D) they lose one arm they are quickly replaced, with the animal sometimes overcompensating,
(E) they lose one arm it is quickly replaced, sometimes with the animal overcompensating,

Video and Text Solution

Meaning Analysis

• Starfish,
  • with anywhere from five to eight arms,
• have a strong regenerative ability, and
  • if one arm is lost
• it quickly replaces it,
  • sometimes by the animal
    • overcompensating and 
    • growing an extra one or two.

• Starfish,
  • with anywhere from five to eight arms,
• have a strong regenerative ability, and

This sentence presents some information about Starfish. They can have 5 to 8 arms, and they have a strong power to regenerate. The presence of “and” indicates the presence of additional information.  

• if one arm is lost
• it quickly replaces it,

If Starfish lose one arm, they can replace it fast. So, we understand that this piece of information is about the regenerative power of Starfish. 

• sometimes by the animal overcompensating and growing an extra one or two.

The last bit if the sentence says that in the process of replacing a lost arm, Starfish sometimes overcompensate and end up growing an extra arm or may be two. So, this part substantiates the point that Starfish has “a strong regenerative ability”.

To sum it all, this sentence presents a few pieces of information about Starfish that can have 5 to 8 arms. They have a very strong power to regenerate. To substantiate this point, the authors adds that if Starfish lose an arm, they can quickly replace it. In the process, they sometimes do more than needed and grow an extra arm or two.

Error Analysis

Structure Error

This sentence uses “if…then…” structure. Generally, the “if…then…” clauses are written in the same structure. However, we do not see the same here. The “if” clause is written in the passive voice while the “then” clause is written in the active voice. This inconsistency in the structure leads to structure error in the sentence because both these clauses can be written in either the active or the passive voice to maintain the identical structure.     

Pronoun Error

The singular pronoun “it” has been used to refer to the plural noun “Starfish”. We know for sure that “Starfish” is a plural noun because it takes the plural verb “have”.

Idiom Error

Although the last bit of the sentence, “sometimes by the animal…” present the meaning fine, the structure of this bit is not precise.

Answer Choice Analysis

Choice A: one arm is lost it quickly replaces it, sometimes by the animal overcompensating and

Incorrect: 4% people chose this option

This choice has errors pointed out in error analysis.

Choice B: one arm is lost it is quickly replaced, with the animal sometimes overcompensating and

Correct

This choice rectifies all the grammatical errors of the original sentence and presents the logical meaning clearly.

Choice C: they lose one arm they quickly replace it, sometimes by the animal overcompensating,

Incorrect (19% people chose this option)

1. Idiom Error

This choice repeats the idiom error we spotted in Choice A with regards to the usage of “sometimes by animal…”.

2. Parallelism Error

The original sentence presents the actions of overcompensating and growing as two separate actions that connected by “and”. The omission of this conjunction violates parallelism because there cannot be a list without conjunction.

Choice D: they lose one arm they are quickly replaced, with the animal sometimes overcompensating,

Incorrect (1% people chose this option)

1. Structure Error

This choice repeats the structure error related to the “if…then…” clauses. They are not in the same voice.

• Pronoun Error

The plural pronoun “they” has been used to the singular noun “one arm”.

• Parallelism Error
  
  

This choice repeats the parallelism error of Choice C.

Choice E: they lose one arm it is quickly replaced, sometimes with the animal overcompensating,

Incorrect (24% people chose this option)

1. Structure Error

This choice repeats the structure error related to the “if…then…” clauses. They are not in the same voice.

• Parallelism Error

This choice repeats the parallelism error of Choice C.

• Idiom Error

This choice repeats the idiom error we noted in Choice A with regards to the usage of “sometimes by animal…”.

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