Whenever a star transforms into a supernova, it exhibits surges of act

Question

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?

(A) Whether LV-426 is of the same size as other stars that have exploded into supernovas
(B) Whether other stars that became supernovas also exhibited periods of dormancy
(C) Whether turbulent activity can indicate that a star is about to transform into an entity other than supernova
(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
(E) Whether the scientists who studied LV-426 in the past considered the possibility that the star’s period of dormancy may not last

Nidzo · Accepted Answer

A) Irrelevant. The size of the star was never a reason behind why it may or may not one day become a supernova.  Incorrect

B) Evaluating whether other stars may have also gone through a period of dormancy before becoming a supernova does not do enough to solidify or weaken the argument. While some stars may have gone on to become supernovas, others may have not. This does not provide enough to evaluate the certainty of the argument.  Incorrect

C) This would without a doubt provide enough everything needed to evaluate the certainty of the argument. If the turbulent activity can indicate that the star can transform into something else, then there cannot be any certainty. However, if turbulent activity indicates that a star will transform into a supernova, then the argument is 100% solidified.  Correct

D) The core temperature is completely irrelevant to the argument.  Incorrect

E) We are told in the passage that scientists dismissed the possibility of LV-426 becoming a supernova because of its dormancy.  Incorrect

Answer C

Gio96 · Answer

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.

Navaneethcs · Answer

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.

AnirudhaS · Answer

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.

RutujaDeshmukh19 · Answer

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.

napolean92728 · Answer

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.

gaurikhanna17 · Answer

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.

AllisonBell · Answer

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,

guddo · Answer

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)

egmat · Answer

Hi gaurikhanna17,

You're right to compare B and C, because both mention other stars and both  feel  relevant. The fastest way to separate them on an Evaluate question is a simple test:  ask the question both ways and see if the answer changes how certain the conclusion is.  The conclusion here is narrow -  the recent turbulent activity makes it certain LV-426 will become a supernova.

Run that test on C: 
- If turbulent activity  can  signal a star turning into something  other  than a supernova - the certainty collapses.
- If it  cannot  - the certainty holds up.

The answer swings the conclusion. That's exactly what an Evaluate answer must do.

Now run it on B - "Whether other stars that became supernovas also exhibited periods of dormancy": 
- If  yes , other supernovas had dormancy periods - so what? LV-426 could still be heading somewhere else.
- If  no , they didn't - still tells us nothing about whether  this  star's current surges guarantee a supernova.

Either way, the certainty of the conclusion doesn't move. B never touches the actual link the author is relying on:  surges of activity - supernova.

There's a second reason B falls flat. Dormancy was the  old  reason scientists dismissed LV-426, and the argument has already moved  past  dormancy - the new claim rests entirely on the recent activity. So B is digging into a side issue the conclusion no longer depends on.

So the split is clean:  C tests the exact inference  (does turbulent activity really mean  supernova  specifically?), while  B is true-but-irrelevant  - it can be answered either way without shaking the conclusion. Whenever you're torn on an Evaluate question, that both-ways swing test is your tie-breaker.

Answer: C

Whenever a star transforms into a supernova, it exhibits surges of act

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Critical Reasoning (CR) Questions

Whenever a star transforms into a supernova, it exhibits surges of act

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards