I think its C

Every other answer choice has verb tense issues imo

OA is C.
I was not able to drill down to any one of the choices. At the end chose A.
Could you elaborate on the answer plz.

A "seems to be one" is awkward and wordy, so I eliminated it right off the bat.

B "conceving and executing" is incorrect. It implies that it is ongoing, since this is a historical sentence and the non-underlined portion of the sentence uses past tense verbs, you need past tense verbs here.

C Correct

D "having been conceived" incorrectly uses the present perfect continuous. The action is not still being conceived and executed by Claudet, so this tense is incorrect and changes the meaning of the original.

E "would have conceived" is the conditional tense, which is inappropriate here. You would use the conditional tense if you were referencing the future from the perspective of the past, but that is not what this sentence is doing, so the use of the conditional is wrong.

(A) In "to be one of Claudet conceiving and executing part of Rodin's enormous production of that period.", "one of" needs to replaced by "that", "conceiving" and "executing" by "conceived" and "executed" respectively.

(B) is wrong because of "of". You cannot introduce the second clause with "of". Replace "of" with "that" and "conceiving" and "executing" with "conceived" and "executed" respectively. There is also an intended meaning issue because of the use the gerunds "conceiving" and "executing" for something that happened in the 19th century. Basically a wrong tense issue.

(D) same mistake as in (B): the "of" issue. Furthermore "having been conceived and executed" is awkward.

(E) "would have conceived and executed" is an hypothetical occurrence (that would have happened only under certain conditions-not stated) while the original sentence tells us that "Camille Claudet conceived and executed part...", only that this conclusion seems inescapable.

(C) no mistake