Hello Everyone!
Let's tackle this question, one issue at a time, and narrow it down to the correct choice! First, let's take a closer look at the original question and highlight any major differences between the options in orange:
The stars, some of them at tremendous speeds, are in motion just as the planets are, yet being so far away from the Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
(A) The stars, some of them at tremendous speeds, are in motion just as the planets are, yet being
(B) Like the planets, the stars are in motion, some of them at tremendous speeds, but they are
(C) Although like the planets the stars are in motion, some of them at tremendous speeds, yet
(D) As the planets, the stars are in motion, some of them at tremendous speeds, but they are
(E) The stars are in motion like the planets, some of which at tremendous speeds are in motion but
After glancing over the options quickly, a few key differences pop out that we can focus on:
1. yet being / but they are / yet / but (Coordinating Conjunctions)
2. placement of the phrase "some of them at tremendous speeds" (Modifiers/Meaning)
3. just as the planets are / like the planets / as the planets (Idioms/Comparisons)
Let's start with #1 on our list: coordinating conjunctions! Whenever we see coordinating conjunctions as one of our key differences, we MUST check to see that they are being used properly. Coordinating conjunctions (for, and, nor, but, or, yet, so) can only be use to connect 2 independent clauses. Let's take a look at each option to figure out if they are using conjunctions correctly. (I've added the non-underlined portion of the sentence to help see the problem.)
(A) The stars, some of them at tremendous speeds, are in motion just as the planets are, yet being being so far away from the Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
independent clause + yet + dependent clause = WRONG
(B) Like the planets, the stars are in motion, some of them at tremendous speeds, but they are being so far away from the Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
independent clause + but + independent clause = OK
(C) Although like the planets the stars are in motion, some of them at tremendous speeds, yet being so far away from the Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
independent clause + yet + dependent clause = WRONG
(D) As the planets, the stars are in motion, some of them at tremendous speeds, but they are being so far away from the Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
independent clause + but + independent clause = OK
(E) The stars are in motion like the planets, some of which at tremendous speeds are in motion but being so far away from the Earth that their apparent positions in the sky do not change enough for their movement to be observed during a single human lifetime.
independent clause + but + dependent clause = WRONG (This is also missing a comma before the conjunction "but.")
There you go - we can eliminate options A, C, & E because they don't use coordinating conjunctions properly!
Now that we have it narrowed down to only 2 options, let's take a closer look at each one and see if we can find any problems:
(B) Like the planets, the stars are in motion, some of them at tremendous speeds, but they are
This is the CORRECT choice! The preposition "like" should always be used after a noun, which it is here.
(D) As the planets, the stars are in motion, some of them at tremendous speeds, but they are
This is INCORRECT. The word "as" should only be used as a conjunction to join two clauses together. Since the phrase "As the planets" isn't a clause with a subject and verb, this doesn't work.
There you have it - option B is our correct choice!
Don't study for the GMAT. Train for it.
