Question

A star will compress itself into a white dwarf, a neutron star, or a black hole after it passes through a red giant stage, depending on mass.

Option A
Option B
Option C
Option D
Option E

(This question is from Official Guide. Therefore, because of copyrights, the complete question cannot be copied here. The question can be accessed at GMAT Club)

Solution

Sentence Analysis

A star will compress itself (Main Subject: ‘a star’; Main Verb: ‘will compress’)
- into a white dwarf, a neutron star, or a black hole (Prepositional phrase – modifies the main verb)
- after it passes through a red giant stage, (Dependent clause – modifies the main verb)

depending on mass. (Comma+Verb-ing modifier. Can modify the preceding clause or the main clause)

The sentence says that after a star passes through a red giant stage, it will compress itself into one of the three possibilities. Which possibility a star compresses itself into depends on the star’s mass.

There is no grammatical issue with the sentence. The only issue in the sentence is that the position of the verb-ing modifier ‘depending on mass’ leads to some confusion around what this modifier modifies. This modifier can modify the preceding clause “it passes through…”, or it can modify the main clause “a star will compress”. A better version of the sentence can remove this ambiguity.

Option Analysis

(A) Incorrect. For the issue pointed above.

(B) Incorrect.

This option has the same confusion in the meaning as option A has.
Besides, there is a potential confusion around the antecedent of the pronoun “its”. In this construction, “its” can also refer to “red giant stage”, the only noun that appears before the pronoun.

Per this option, “a star’s mass” passes through a red giant stage and compresses itself into a white dwarf. The star does these things, not the star’s mass.
The “if” needs to be “replaced with “whether” – “if” is used very commonly in this way in informal contexts, but in formal English, “whether” is used.

(D) Correct. The meaning issue present in the original sentence has been resolved by changing the structure of the sentence.

(E) Incorrect. This option has the same error as option C has.

This solution was created by Anish Passi and Chiranjeev Singh.

If you have any doubts regarding any part of this solution, please feel free to ask in the comments section.

Anish Passi

With over a decade of GMAT training experience, top 1 percentile scores on the CAT and GMAT, Anish is one of the most qualified GMAT coaches in India. He has founded and served as Director in two edu-tech startups in the past. An alumnus of IIM Ahmedabad and McMaster University, Canada, he strongly believes in the right way of learning, and in learning to grow and not just to get a score, an admission or a job. Anish offers private tutoring (online and in-person), and workshops for groups. His sessions are often sprinkled with jokes that only he finds funny (you've been warned). To connect with him, write to him at a@TheGMATCo.com