Last visit was: 14 Jul 2026, 20:58 It is currently 14 Jul 2026, 20:58
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
User avatar
Bunuel
User avatar
Math Expert
Joined: 02 Sep 2009
Last visit: 14 Jul 2026
Posts: 111,929
Own Kudos:
Given Kudos: 109,329
Products:
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 111,929
Kudos: 827,485
 [15]
2
Kudos
Add Kudos
13
Bookmarks
Bookmark this Post
User avatar
Nidzo
Joined: 26 Nov 2019
Last visit: 02 Aug 2025
Posts: 958
Own Kudos:
1,508
 [5]
Given Kudos: 59
Location: South Africa
Posts: 958
Kudos: 1,508
 [5]
4
Kudos
Add Kudos
Bookmarks
Bookmark this Post
User avatar
Gio96
Joined: 27 Jan 2021
Last visit: 24 May 2026
Posts: 36
Own Kudos:
Given Kudos: 56
Posts: 36
Kudos: 7
Kudos
Add Kudos
Bookmarks
Bookmark this Post
avatar
Navaneethcs
Joined: 07 Feb 2021
Last visit: 03 Oct 2022
Posts: 12
Own Kudos:
6
 [2]
Given Kudos: 545
Posts: 12
Kudos: 6
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Gio96
Hi Expert, I have a doubt about choice C.

I agree that if we answer yes to that question, we decrease our belief in the conclusion, but if we answer NO, how this can help us evaluate the conclusion?

We only know that when a star is about to transform into a supernova, it exhibits TA, but we can't say the contrary, that is, that when a star exhibits TA is about to transform.

So, even if C is negated, we could have a possibility that the star doesn't transform at all.


Could you please clarify?
Regards.

Let me try to help here.

Let
A - a star transforms into a supernova
B - It exhibits surges of activity

In the first line, it says A->B (ie: A leads to B).
It does not say whether B->A (ie: a surge in activity may not lead to a supernova. It may so happen that a surge in activity might lead to its death, etc.)

But the scientists are now predicting a surge in activity will CERTAINLY lead to an explosion into a supernova. (ie: B ->A.)

So in C, we are essentially getting the answer for whether B->A ( ie: if it does not lead to something other than a supernova, then we can conclude B->A)

Regards.
User avatar
AnirudhaS
User avatar
LBS Moderator
Joined: 30 Oct 2019
Last visit: 25 Jun 2024
Posts: 773
Own Kudos:
898
 [2]
Given Kudos: 1,575
Posts: 773
Kudos: 898
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Gio96
Hi Expert, I have a doubt about choice C.

I agree that if we answer yes to that question, we decrease our belief in the conclusion, but if we answer NO, how this can help us evaluate the conclusion?

We only know that when a star is about to transform into a supernova, it exhibits TA, but we can't say the contrary, that is, that when a star exhibits TA is about to transform.

So, even if C is negated, we could have a possibility that the star doesn't transform at all.


Could you please clarify?
Regards.
Conclusion: it is now certain that LV-426 will explode in to a supernova.

Part 1 (Yes)
(C) Whether turbulent activity CAN indicate that a star is about to transform into an entity other than supernova

Part 2 (No)
(C) Whether turbulent activity CANNOT indicate that a star is about to transform into an entity other than supernova


In both cases, it evaluates the argument. I guess you got confused with finding the assumption of the argument; that is when we use negation.
User avatar
RutujaDeshmukh19
Joined: 08 Jul 2023
Last visit: 15 May 2025
Posts: 20
Own Kudos:
13
 [3]
Given Kudos: 23
Location: India
Posts: 20
Kudos: 13
 [3]
2
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
­Let us break down the argument and understand it in a better way:

Whenever a star transforms into a supernova, it exhibits surges of activity prior to the transformation. 
  • Surges of activity prior to transformation is the sign that a star is transforming into supernova

The star LV-426 has recently been exhibiting signs of turbulent activity. 
  • We can predict that the scientists are probably saying that LV-426 is going to convert to a supernova.

In the past, scientists speculated over whether LV-426 could become a supernova, but dismissed the possibility since the star was dormant for a prolonged period of time. 
  • Since, the star was dormant for a longer period of time, scientists dismissed the possibility of it converting into a supernova.

Given the star’s recent activity, it is now certain that LV-426 will explode in to a supernova.
  • But, again due to surges in activity, it is now guranteed that LV-426 will explode into a supernova.

We need to choose an option that affects the conclusion that LV-426 will explode into a supernova 

(A) Whether LV-426 is of the same size as other stars that have exploded into supernovas. - Incorrect
  • Size of the stars is not a matter of concern.
  • Nothing is mentioned in the argument pertaining to the size of the stars while converting into supernovas

(B) Whether other stars that became supernovas also exhibited periods of dormancy. - Incorrect
  • There might be cases where the stars did not exhibit dormancy but still converted to supernovas. 
  • Hence, this answer choice should be eliminated

(C) Whether turbulent activity can indicate that a star is about to transform into an entity other than supernova. - Correct
  • If YES -->> There is the possibility that the conclusion 'LV-426 will convert to a supernova' might not come true as LV-426 might convert into a different entity.
  • If NO -->> There is a possibility that LV-426 will convert to a supernova since there is no other entity that exhibits a surge in activity when converting to an entity.

(D) Whether a period of dormancy can reduce a star’s core temperature to a level at which the star can no longer exhibit surface-level activity. - Incorrect
  • Argument has not mentioned anything specifically about the star’s core temperature.
  • Hence, this option choice is irrelevant.

(E) Whether the scientists who studied LV-426 in the past considered the possibility that the star’s period of dormancy may not last. - Incorrect
  • If YES -->> If they might have considered the possibility that the dormancy period might last, why did they speculate that the star will not convert to a supernova in the first place. This option is changing the premise that 'dismissed the possibility since the star was dormant for a prolonged period of time'  (which cannot be modified in any case on the GMAT)
  • If NO -->> If they have not considered that the dormancy period may last, again it casts a doubt on the premise.
  • Hence, this answer choice should be eliminated.
­
User avatar
napolean92728
User avatar
CAT Forum Moderator
Joined: 13 Oct 2024
Last visit: 09 Apr 2026
Posts: 278
Own Kudos:
Given Kudos: 233
Status:Death is nothing, but to live defeated and inglorious is to die daily.
Posts: 278
Kudos: 101
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The correct answer is (C) Whether turbulent activity can indicate that a star is about to transform into an entity other than supernova.
The argument concludes that LV-426 will "certainly" become a supernova based on its turbulent activity. The critical assumption is that this turbulent activity specifically indicates an upcoming supernova and not something else. If turbulent activity could signal other stellar transformations, then we can't be certain that a supernova will occur.

Let's analyze why the other options are incorrect:
(A) The size comparison to other supernovae isn't directly relevant to evaluating whether this particular star's current behavior indicates it will become a supernova. The argument hinges on the interpretation of turbulent activity, not size.

(B) While dormancy patterns in other supernovae might be interesting, the argument already acknowledges that scientists previously dismissed supernova possibility due to dormancy. The current conclusion is based on the new turbulent activity, not the dormancy period.

(D) This addresses what dormancy might do to a star's core temperature, but the argument has already moved past the dormancy phase to focus on the new turbulent activity as the key indicator of an impending supernova.

(E) This looks at past scientific considerations but doesn't help evaluate the current argument that turbulent activity necessarily means a supernova will occur. The scientists' past thoughts on the duration of dormancy don't address whether the current turbulent activity specifically indicates a supernova.
User avatar
gaurikhanna17
Joined: 16 Jan 2025
Last visit: 14 Jul 2026
Posts: 43
Own Kudos:
Products:
Posts: 43
Kudos: 25
Kudos
Add Kudos
Bookmarks
Bookmark this Post
in this i have a doubt between option B and option C can someone please explain me how i can rule out option B. I got stuck between these two options and landed up choosing B in the end.
User avatar
AllisonBell
User avatar
Manhattan Prep Instructor
Joined: 12 May 2026
Last visit: 14 Jul 2026
Posts: 71
Own Kudos:
Affiliations: Manhattan Prep
GMAT Focus 1: 725 Q84 V90 DI84
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
GMAT Focus 1: 725 Q84 V90 DI84
Posts: 71
Kudos: 26
Kudos
Add Kudos
Bookmarks
Bookmark this Post
gaurikhanna17
in this i have a doubt between option B and option C can someone please explain me how i can rule out option B. I got stuck between these two options and landed up choosing B in the end.
Great question! I think this really hinges on the reasoning the author uses to support the conclusion.

Choice (B) helps to establish similarities or differences between LV-426 and other stars that have become supernovas. That would be helpful if that was the main reasoning used to establish the conclusion. But this argument doesn’t rest on a comparison. In other words, the premises aren’t all about using other stars to prove that LV-426 will become a supernova. And there’s no indication that scientists are worried that stars can’t become supernovas after periods of dormancy, so this isn’t answering some lingering question raised by the premises.

Choice (C), on the other hand, addresses the logic of the premises. They rely on a correlation between signs of activity and becoming a supernova. The activity is the only reason given to believe this star will be a supernova, so if it could mean something else, that would really hurt the argument. And if we could rule out that it means something else, that would really help the argument.

A takeaway from this argument is that evaluating arguments is about looking at the relationship between the premises and the conclusion, not just at the conclusion. That will help us understand how the author is trying to prove their claim, and where they fall short.

For more CR practice questions and teacher-written explanations, check out ManhattanPrep's Free QBank & Starter Kit.


Best,
User avatar
guddo
Joined: 25 May 2021
Last visit: 14 Jul 2026
Posts: 1,555
Own Kudos:
13,165
 [1]
Given Kudos: 32
Posts: 1,555
Kudos: 13,165
 [1]
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Whenever a star transforms into a supernova, it exhibits surges of activity prior to the transformation. The star LV-426 has recently been exhibiting signs of turbulent activity. In the past, scientists speculated over whether LV-426 could become a supernova, but dismissed the possibility since the star was dormant for a prolonged period of time. Given the star’s recent activity, it is now certain that LV-426 will explode in to a supernova.

Which of the following would it be most useful to determine in order to evaluate the argument?


The argument says stars that become supernovas show prior activity, and LV-426 is now showing activity. The key gap is that activity may be necessary before a supernova, but that does not mean activity proves a supernova. The activity could have some other explanation.

(A) Whether LV-426 is of the same size as other stars that have exploded into supernovas

This may be somewhat relevant scientifically, but it does not directly test the argument’s main move from “turbulent activity” to “certain supernova.”

(B) Whether other stars that became supernovas also exhibited periods of dormancy

This could weaken the old reason for dismissing the possibility, but it does not show that LV-426’s current activity makes a supernova certain.

(C) Whether turbulent activity can indicate that a star is about to transform into an entity other than supernova

This is correct. If turbulent activity can also indicate some other transformation, then LV-426’s activity does not prove that it will become a supernova. If turbulent activity only points to supernova transformation, the argument becomes much stronger.

(D) Whether a period of dormancy can reduce a star’s core temperature to a level at which the star can no longer exhibit surface-level activity

This is not useful. LV-426 is already exhibiting activity, so we know dormancy did not make surface-level activity impossible.

(E) Whether the scientists who studied LV-426 in the past considered the possibility that the star’s period of dormancy may not last

This is not central. What past scientists considered does not determine whether the current activity proves that LV-426 will become a supernova.

Answer: (C)
Moderators:
GMAT Club Verbal Expert
7395 posts
702 posts