Molecules

I had to read this one several times, but I also believe the answer should be D. The argument is saying that because these things are formed in the labratory only under particular conditions, then the ones that naturally occured must also have formed under the same particular conditions.

(A) Irrelevant. Who cares how they were confirmed.
(B) This has nothing to do with the things found in nature, though maybe we could learn about the conditions in which they formed on the meteor. Different question.
(C) Nothing to do with the argument.
(D) Now this is saying that the things found in nature are different than the ones they made in the lab. Meaning that maybe they were made under different conditions. Best answer
(E) Doesn't matter how the shungite thing was formed, just the other thingy.

Only D passes the PoE test.

Well, I am not totally agree with above reasons to support D. Don't just jump to say D is the best. Wait for other options to check.

It is mentioned that the fullerenes are spherical molecule but nothing is mentioned regarding their arrangement. Conclusion says the distinctive conditions of P & T required to find the fullerenes may be helpful to hypotheses about the Earth's crust...

So, we need to show some missing point OR flaw in the assumption to doubt this conclusion. As per D, the crystalline structure is UNKNOWN. The combination of P & T for naturally occuring may be way more and distinct than that in the lab. May be more factors were there to decide the unknown crystalline structure. So, it is unreasonable to conclude that the distinctive conitions of P & T in lab may be helpful to evaluate the Earth's crust....fullerenes. Thus, this reason brings the conclusion into doubt.

A, B, C and E are either out of scope or stating one of the premises in the argument.

Doesn't B suggest that the fullerences could have come from a meteor that landed on earth? If that were the case, it would tell us nothing about the conditions on earth at that time, as it was formed elsewhere.

B is irrelevant to the argument. D states that scientists are unaware of the molecule location and hence cannot possibly determine the conditions that led to the synthesis and existence of the molecule.

There are two things which are critical to the plan
1) The exact location of the molecule
2) The exact conditions of pressure and temperature

D makes condition 1) vulnerable. While B suggests the possibility of extraterrestrial source, it does not questions the "natural existence" of the molecule else where on earth which is relevant to the argument.

B makes condition 2 vulnerable. If the fullerenes were formed in space, then they tell us nothing about the conditions on the earth's crust when they were formed.

I think your missing the final line- the geologists hypothesis about the Earth's crust

Also, the argument says that the molecules will provide a case for the scientist to evaluate the earth's crust at the time the molecules were formed.

But what if the molecules are not formed but are arranged in some unknown crystalline structure. In that case the argument is weakened.