Dear Friends,

Here is a detailed explanation to this question-

Concepts tested here: Grammatical Construction + Idioms + Awkwardness/Redundancy

. "would + base form of verb" is a correct construction for referring to a hypothetical future action.
. “would + have + past participle" construction is used to refer to a hypothetical action in the past.

A: This answer choice fails to form a complete sentence; both "Were it not...core" and "instead its own weight would cause a star to collapse" are dependent clauses, so there is no independent subject for the modifiers to act upon. Further, Option A uses the passive voice construction "its own weight would cause a star to collapse", leading to awkwardness and redundancy.

B: This answer choice fails to form a complete sentence; both "Were it not...core" and "instead a star would have collapsed under its own weight" are dependent clauses, so there is no independent subject for the modifiers to act upon. Further, Option B incorrectly uses the "would + have + past participle ("collapsed" in this sentence)" construction to refer to a hypothetical future action; please remember, "would + base form of verb" is a correct construction for referring to a hypothetical future action, and “would + have + past participle" construction is used to refer to a hypothetical action in the past.

C: This answer choice incorrectly uses the construction "would have to be collapsing" to refer to a hypothetical future action; please remember, "would + base form of verb" is a correct construction for referring to a hypothetical future action.

D: Correct. This answer choice uses the independent clause "a star would collapse under its own weight"; thus, it acts upon the independent noun "a star" with the active verb "would collapse" to form a complete thought, leading to a complete sentence. Further, Option D correctly uses the "would + base form of verb ("collapse" in this sentence)" to refer to a hypothetical future action. Additionally, Option D is free of any awkwardness or redundancy.

E: This answer choice incorrectly uses the "would + have + past participle ("caused in this sentence)" construction to refer to a hypothetical future action; please remember, "would + base form of verb" is a correct construction for referring to a hypothetical future action, and “would + have + past participle" construction is used to refer to a hypothetical action in the past.

Hence, D is the best answer choice.

All the best!
Experts' Global Team
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This question can be solved by the If then case

If .... were...., then ..... would

If the sky were to fall, then we would all be dead

can also be written as

Were the sky to fall, we would all be dead.

so D

daagh GMATNinja - is this correct?

The use of instead seems wrong here. Ruling out A & B

C : "would have to be collapsing" is incorrect

D : straight forward and concise

E : The statement is wordy, also "its" cannot relate to star as star is in a possessive form "star's collpase" and not "star"
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Were it not for the fusion-powered heat and radiation that rush from its core, instead its own weight would cause a star to collapse.
A. instead its own weight would cause a star to collapse
B. instead a star would have collapsed under its own weight
C. a star would have to be collapsing under its own weight
D. a star would collapse under its own weight
E. its own weight would have caused a star’s collapse

This is a form of if construction and sets up a hypothetical condition. This construction requires would.

If I were rich I would donate money to charity.

This leaves us with options C&D. would have to be is wrong construction.

Correct option D

IMO E.

Since "were it not.." starts the sentence, use of instead will be redundant. Hence, Option A and B are out.
Now, to make the sentence parallel, we have to start the second part we have to use "its own weight..".

Hence, I would go with E.

2:3 split. the subject is the star so it should be followed. C sounds weird and doesnt make much sense. D

D, straight forward, nothing else makes sense
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"its core" modifies the star.. and hence down to C and D..
D is uncomplicated and conveys the meaning straight!

Suarabh

You couldn't be more right.
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This question is based on the structure of Conditional sentences.

Conditional sentences can either begin with the conjunction ‘if’ or directly with the verb. The construction of this sentence is of the latter type.

This kind of conditional sentence conveys the meaning that if a hypothetical condition were to be fulfilled, a hypothetical result would ensue. The construction of such a sentence is fixed:
If + subject + verb in the past subjunctive, subject + would + verb in the base form/simple present
Since in this sentence, the conditional part of the sentence is not underlined and therefore non-negotiable, the verb form in the underlined portion has to be according to the structure of the hypothetical conditional sentence.

The adjective ‘instead’ is redundant in a conditional sentence. ‘Instead’ implies a substitute for something. Since both options A and B contain the word ‘instead’, they can be ruled out.

Option C contains the incorrect verb form ‘have to be collapsing’. The correct form is ‘would collapse’. So, Option C is incorrect.

Option D contains the correct verb form and construction of a hypothetical conditional sentence. So, this is the best option.

Option E contains the incorrect verb form. The present perfect tense is used in a past conditional sentence with the past perfect tense in the conditional clause. The option also has a rather ambiguous phrasing – its own weight would have caused a star’s collapse. The antecedent of the pronoun ‘its’ is not completely clear. So, Option E can also be eliminated.

Therefore, D is the most appropriate option.

Jayanthi Kumar.
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This question seems to be a hypothetical situation and hence could be written with would verb or would have verb

Is there was a construction with Would have in the options, would that be correct or incorrect? Would love to here the forum's take on the same.

e.g.

Were it not for the fusion-powered heat and radiation that rush from its core, a star would have collapsed under its own weight