Sentence Correction (SC) | Re: When chemist Amedeo Avogadro (1776 – 1856) posited that equal volumes

Though I answered this question wrong, later, I came to know where I did wrong.
I narrowed down to C and D.

One flaw in C is use of present perfect tense that I did. Another one is construction of sentence.
X, but Y, but Z.
It seems wrong to me.

In D sentence construction is as below.
X, and Y, but Z.

Please give feedback if my explanation is correct here.

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