Critical Reasoning

All,

Please see the question below:

Although fullerenes – spherical molecules made entirely of carbon – were first found in the laboratory, they have since been found in nature, formed in fissures of the rare mineral shungite. Since laboratory synthesis of fullerenes requires distinctive conditions of temperature and pressure, this discovery should give geologists a test case for evaluating hypotheses about the state of the Earth’s crust at the time these naturally occurring fullerenes were formed.

Which of the following, if true, most seriously undermines the argument?

(A) Confirming that the shungite genuinely contained fullerenes took careful experimentation.
(B) Some fullerenes have also been found on the remains of a small meteorite that collided with a spacecraft.
(C) The mineral shungite itself contains large amounts of carbon, from which the fullerenes apparently formed
(D) The naturally occurring fullerenes are arranged in a previously unknown crystalline structure
(E) Shungite itself is formed only under distinctive conditions.

[spoiler]OA: D

I was able to get to the correct answer by process of elimination, but I'm still sitting on the fence on answer choice D. It seems like the other ACs (A, B, C and E) are irrelevant, so D must be the answer, but how exactly does D undermine the argument? If anyone can shed light on this, would be greatly appreciated. Thanks.[/spoiler]

I would say that D undermines the argument because the author is arguing that the discovery of naturally occurring fullerenes will give us a test case for evaluating hypotheses on the state of the earth's crust when the naturally occurring fullerenes formed...

HOWEVER, if the fullerenes that formed naturally are substantially different ("previously unknown crystalline structure") from the lab-created fullerenes, then they likely were created under circumstances somewhat different than the ones the lab used to create the fullerenes, therefore, we can't hypothesize as to the earth's crust at the time of their formation.

my opinion

If the shingite is formed from an unknown crystalline structure of carbon.We need to know what kind of environment led to the formation of that carbon

in lab

carbon type X --> high temp and pressure --> fullerness

In nature

carbon type Y(unknown structure)-->(wat happned??)-->fullerness

hope the above is helpfull

This is great. Thanks, guys.

IMO is B

the material is created in different environment so we can not know the state of Earth's crust and B destroy conclusion.

duongthang wrote:IMO is B

the material is created in different environment so we can not know the state of Earth's crust and B destroy conclusion.

B--goes outside the context of the discussion. Keep in mind, the discussion is about comparison of lab material Vs. natural material. Is it the same? Can lab synthesized material be used to determine the earth's crustal composition.

D--weakens the arguement because you're comparing lab created material with natural material that has a different chemical composition.

myohmy wrote:I would say that D undermines the argument because the author is arguing that the discovery of naturally occurring fullerenes will give us a test case for evaluating hypotheses on the state of the earth's crust when the naturally occurring fullerenes formed...

HOWEVER, if the fullerenes that formed naturally are substantially different ("previously unknown crystalline structure") from the lab-created fullerenes, then they likely were created under circumstances somewhat different than the ones the lab used to create the fullerenes, therefore, we can't hypothesize as to the earth's crust at the time of their formation.

Great explanation!

Hi,

I discussed this question in some depth over here: https://www.beatthegmat.com/gmat-prep-fu ... tml#201811