usage of which

[iamdccc]

Like many other theropods discovered in the Yixian Formation, a coat of filamentous structures was preserved with the fossil skeleton, which are commonly recognized as the precursors of feathers.

(A) a coat of filamentous structures was preserved with the fossil skeleton, which are commonly recognized as the precursors of feathers.
(B) the fossil skeleton had been preserved with a coat of filamentous structures, which are commonly recognized as the precursors of feathers.
(C) the fossil skeleton was preserved with a coat of filamentous structures commonly recognized as the precursors of feathers.
(D) a coat of filamentous structures, which are commonly recognized as the precursors of feathers, had been preserved with the fossil skeleton.
(E) a coat of filamentous structures, commonly recognized as the precursors of feathers, was preserved with the fossil skeleton.

suppose we used 'was' in B instead of 'had been' , then which out of B and C would be the correct answer

[messi10]

Hi,

I will still prefer C.

If we ignore the "had been" part in B then it comes down to the use of which. In this case, the comma + which.... make that part of the sentence a non-essential modifier. This does not make it grammatically incorrect but makes the following part optional:
"commonly recognized as the precursors of feathers"

Regards

Sunil

[jnelson0612]

What is the original source and answer for this question? All questions in this forum must have the original source noted.