Beyond the most basic principles of auditory scene analysis

Beyond the most basic principles of auditory scene analysis, the "cocktail party effect" has for years been stimulating a stronger understanding of aural segregation, to describe the effect of several voices dissolving into one.

A. the "cocktail party effect" has for years been stimulating a stronger understanding of aural segregation, to describe - Infinitive is not required as no purpose is intended.
B. the "cocktail party effect" has stimulated a stronger understanding of aural segregation for years, and so describing - Comma+And requires an IC. Also, 02 verbs on both side of and are not parallel. It should be just present participle 'Descibing'
C. the "cocktail party effect", which has stimulated a stronger understanding of aural segregation for years, describes - Correct
D. the "cocktail party effect", which has for years been stimulating a stronger understanding of aural segregation and has described - No verb for 'CPE'. Fragment
E. the "cocktail party effect," having stimulated a stronger understanding of aural segregation for years, to describe - Noun, Present participle/Noun Modifier, Infinitive....hence no verb for 'CPE. Fragment.

because sc test our ability to analyse meaning /logic, if the sentence contain many new words or too deeply specialized knowledge, gmat disadvantage the non native , going against the fact that gmat become a international test for all

this sentence contain specialized knowledge which we can not meet even in the rc passage.

I will igore this sentence

Core meaning of sentence: Cocktail party effect is merging of several voices into one. I will summarize Cocktail Party Effect as CPE.
In the sentence the verb describe is used.
CPE describes merging of several voices into one.
(A) illogical meaning- CPE has not been doing something for years to describe a phenomenon. (out)
(B) missing verb. CPE is the subject... no verb (out)
(C) <<Modifier phrase>>, [subject] = CPE, which [this part is non essential modifier, it gives us extra info about CPE], [verb] describes merging of serval voices into one. correct answer
(D)modifier, CPE, followed by modifier which and has described. And introduces forced parallelism. Not needed here. That leaves no verb for CPE. out!!
(E) modifier, CPE, participle phrase, to describe. [no verb for CPE] (OUT)

Correct answer => C