An archaeological excavation at
what might have been a workshop where statues were reproduced yielded 1,532 fragments of human figures, including 7 intact statues.
Option Elimination -
(A) what might have been a workshop where statues were reproduced yielded 1,532 fragments of human figures, including - " what might have been a workshop" is a noun clause acting as an object of a preposition "at." The usage of present perfect "have been" is correct as the "speculation" of this place being a workshop started in the past and continuous to the present. Comma + including can modify the clause and, more importantly, the nearest noun, as GMATIntensive has also pointed out. Here, "including" modifies the "human figures" and it doesn't make sense to say that fragments included "intact statues." Wrong.
(B) what might have been a workshop where statues were reproduced yielded 1,532 fragments of human figures and - ok
(C) the site of a possible workshop where statues were reproduced yielded 1,532 fragments of human figures and - We can say "digital workshop," "Gen AI workshop," "foundry workshop," but there is nothing like "possible workshop," or "impossible workshop." - Wrong.
(D) the site of a possible workshop where statues were reproduced yielded 1,532 fragments of human figures, including - the same issue as of C and comma + including.
(E) the site of a possible workshop where statues might have been reproduced yielded 1,532 fragments of human figures, including- the same issue as of C and comma + including.