Hello Everyone!
Let's tackle this question, one thing at a time, and narrow down the options to find the right answer quickly! To get started, here is the original question with any major differences between the options highlighted in orange:
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,
There is a lot you could focus on with this sentence, but let's start with 2 major differences and narrow things down from there:
1. Pronoun-Antecedent Agreement (it vs. they)
2. Intended Meaning (sometimes by the animal vs. sometimes overcompensating)
Let's start with #1 on our list: pronoun-antecedent agreement. If we look closely, we can see that the subject of the sentence is Starfish, which is a plural subject that requires a plural pronoun. Let's see which options handle this correctly, and eliminate those that don't:
(A) one arm is lost it quickly replaces it, sometimes by the animal overcompensating and --> WRONG
(The singular pronoun "it" is referring back to the plural "starfish," which doesn't match up!)
(B) one arm is lost it is quickly replaced, with the animal sometimes overcompensating and --> OK
(The pronoun "it" here is referring back to the lost arm, which is fine. This sentence doesn't have a pronoun that refers back to "starfish," so let's keep it for later.)
(C) they lose one arm they quickly replace it, sometimes by the animal overcompensating, --> OK
(The pronoun "they" is clearly referring back to the plural "starfish," which matches. The later pronoun "it" is clearly referring back to the lost arm, so let's keep this for later.)
(D) they lose one arm they are quickly replaced, with the animal sometimes overcompensating, --> WRONG
(While the first plural "they" refers back to the plural "starfish," there's a problem with the second "they." In this case, it should be a singular pronoun to match up with the singular lost arm it's referring back to. If we read this sentence as it is, it actually says that if starfish lose an arm, the entire starfish is replaced! That's not the meaning we're trying to convey, so let's rule this one out.)
(E) they lose one arm it is quickly replaced, sometimes with the animal overcompensating, --> OK
(The plural "they" is clearly referring back to the plural "starfish." The singular "it" is clearly referring back to the singular arm. So let's keep this for later!)
We can eliminate options A & D due to pronoun-antecedent agreement problems!
Now, let's move on to #2 on our list: where to put the word "sometimes." Let's take a closer look at each option to determine if the word "sometimes" is placed in the proper place to convey the right meaning:
(B) one arm is lost it is quickly replaced, with the animal sometimes overcompensating and
This is CORRECT! The word "sometimes" is being used as an adverb here to modify the verb "overcompensating." This means that the starfish only overcompensate sometimes, and other times they don't. Since that's the meaning we're looking to convey, this is the correct choice!
(C) they lose one arm they quickly replace it, sometimes by the animal overcompensating,
This is INCORRECT because the word "sometimes" is tied to the phrase "by the animal," rather than the verb "overcompensating." This creates a bit of a nonsense phrase - is it trying to say that sometimes the starfish replaces its own arm, and sometimes another animal does it? Or is it saying that sometimes the animal replaces a lost arm by overcompensating, and sometimes it replaces the arm using some other method? Confusing, right? So let's rule this one out because it's incredibly confusing.
(E) they lose one arm it is quickly replaced, sometimes with the animal overcompensating,
Again, this is INCORRECT because tying to word "sometimes" to the phrase "with the animal" muddles the meaning. In this sentence, it's saying that the lost arm is sometimes replaced WITH the animal overcompensating, and sometimes it's replaced WITHOUT the animal overcompensating. Another confusing scenario, right? Let's rule this one out too!
There you have it - option B is the correct choice because it conveys a clear meaning, and it uses pronouns correctly!
Don't study for the GMAT. Train for it.
