Contemporary cognitive scientists maintain that emotions

Hi ameyaprabhu, the issue is that no source on parallelism can ever substitute for meaning interpretation. This is because the grammatical similarity between various parts of the sentence must support the intended meaning.

Hence, it becomes important that you understand the intended meaning. Here, the intended meaning is that emotions evolved to help animals:
i) survive in hostile environments and
ii) procreate

So, survive and procreate need to be grammatically similar. Hence D and E are eliminated.

However, let's take your interpretation: emotions...evolved...to help animals...and to procreate

So, as per your interpretation, D and E are the only viable choices. At this stage, you need to look one level deeper into options D and E,

Option D: Notice that which would modify products. There are couple of issues with this. For one thing, one would ideally have liked products to be placed close to which. Also, the real intent is that which should modify feelings.

Option E: This is not a complete sentence at all! After and that, one would expect a clause (since that is used as a conjunction here). However, there is no verb in this case at all. The core of the sentence is: ...and that feelings reflecting the interpretation of emotions. It should have been: ...and that feelings reflect the interpretation of emotions. In this case, reflect would be the verb, fixing the sentence.

Hence, with D and E definitely being incorrect, you should reconsider your meaning interpretation and fall back on options A, B and C.

p.s. Our book EducationAisle Sentence Correction Nirvana discusses the various Parallelism nuances, their application and examples in significant detail. If someone is interested, PM me your email-id; I can mail the corresponding section.