In the past several years, astronomers have detected more than 80 mass

The correct route to solve this issue is through the idiom first. Anytime we use as large, it should be completed by another as – as large as.
We can thus eliminate A, B and E; between C and D, we can eliminate D for fouling ‘which’ pronoun touch rule. When there is an eligible noun such as ‘Jupiter’, ‘which’ cannot jump over it and modify the planets

In the past several years, astronomers have detected more than 80 massive planets, most of them as large or larger than Jupiter, which circle other stars.


(A) most of them as large or larger than Jupiter, which circle

(B) most of them as large or larger than Jupiter and circling

(C) most of them at least as large as Jupiter, circling

(D) mostly at least as large as Jupiter, which circle

(E) mostly as large or larger than Jupiter, circling

Hello kunalarya,

We hope this finds you well.

Having gone through the question and your query, we believe that we can help resolve your doubt.

The use of the modifier "mostly" is incorrect in this question, as "mostly" is an adverb and the modifying phrase must modify the noun "planets". Options C, D, and E are incorrect, in part, because they modify "planets" with "mostly"; please remember, adverbs can only modify verbs and adjectives; adjectives modify nouns.

Further, Option D would not be correct, even if "most of them" was used because in it "which circle" incorrectly refers to "Jupiter" rather than "planets".

We hope this helps.
All the best!
Experts' Global Team

thank you for your reply !
However, the last line/ scenario is still not clear to me. if you look at the verb it's plural 'circle' not 'circles', should not it jump over Jupiter and go to planets? Also, we always focus/ give priority to meaning in GMAT, so by meaning Jupiter is not the one circling other stars?
Could I put forward my point ?

In the past several years, astronomers have detected more than 80 massive planets, most of them as large or larger than Jupiter, which circle other stars.

(A) most of them as large or larger than Jupiter, which circle

(B) most of them as large or larger than Jupiter and circling

(C) most of them at least as large as Jupiter, circling

(D) mostly at least as large as Jupiter, which circle

(E) mostly as large or larger than Jupiter, circling

The first half of your post all seems correct to me -- your modified answer choice does change the meaning, as you point out (it's then only the large planets that are circling stars) but it's otherwise fine.

As for the word "mostly", I've never given it too much thought, so perhaps someone else will be able to say something more clarifying than I can. It seems we do use "mostly" and "most of" interchangeably in many situations. But if you think of this sentence:

Mei's application forms were mostly filled in.

this could mean one of two things. It could mean that Mei has a lot of forms, and has filled in most of them, and hasn't even started on a few of them. But it could also mean that Mei has a lot of forms, and has mostly filled in each of them. I'd tend to read the sentence to have this second meaning, because we can express the first meaning in a different way: "Most of Mei's application forms were filled in." But (as your dictionary example of the teenage band illustrates) we use "mostly" to have that first meaning, i.e. to mean "most of", sometimes too. So for me the issue isn't one of strict correctness, but rather of ambiguity -- if the word "mostly" could be read to mean two different things, I'd want to replace it with words that express the intended meaning more precisely. A sentence like the vases are mostly red could mean most of the vases are red and the rest are orange, or that each vase is mostly red and partly orange (or some other colour). That's a sentence I'd want to rephrase, at least if the meaning was "most of the vases are red". But in the teenage band sentence from the dictionary, there's really only one sensible way to interpret the word 'mostly', so there is no ambiguity, and I don't see an issue with using "mostly" in that way. In the planet sentence in this thread, I don't like the word "mostly", but I don't think that's decisive here -- it really can't mean "most of each planet is as large as Jupiter", because that makes no sense, but I don't like that I even have to think about what the word means, so I prefer to replace it with something more immediately comprehensible. But there I'm just applying a principle of good writing, and not a rule of usage or grammar.

Though it occurs to me that a planet is, by the definition of 'planet', something that orbits a star, so it's not clear to me (even in the OA) what purpose the last part of the sentence serves.

Hi,

There is a difference in the meaning between the two sentences cited by you. To understand the same, please have a look at the following sentences:

1. I saw some dogs sitting outside the house.
2. I saw some dogs that sit outside the house.

In the first sentence you are talking about those dogs who were sitting outside the house when you spotted them. However, in the second sentence you are talking about a category of dogs and this category of dogs sits outside the house. So, in the second construction you are describing a general feature of these dogs.

Do you now see how the description of the planets changes with the change in the construction (from –ing modifier to that clause)?



Thanks,

Neeti.

Doesn't Circling modify Jupiter in option C,

shouldn't it have been

"most of them at least as large as Jupiter and circling"