As the above poster has noted, we need appearS because of "dinosaur"

While digging in the Egyptian desert, huge fossil bones have been found by paleontologists, which appears to have been the second most massive dinosaur that ever lived.

A. huge fossil bones have been found by paleontologists, which appears to have been
B. huge fossil bones have been found by paleontologists, which appear to be from
C. it appears that paleontologists have found huge fossil bones that are from
D. paleontologists have found huge fossil bones from what appears to be
E. paleontologists have found huge fossil bones, which are from what appear to be

While digging in the Egyptian desert, huge fossil bones have been found by paleontologists, which appears to have been the second most massive dinosaur that ever lived.


A. huge fossil bones have been found by paleontologists, which appears to have been

B. huge fossil bones have been found by paleontologists, which appear to be from

C. it appears that paleontologists have found huge fossil bones that are from

D. paleontologists have found huge fossil bones from what appears to be

E. paleontologists have found huge fossil bones, which are from what appear to be

Dear Hugoba,
I'm happy to respond. I'm sorry that there was a little delay: during the holidays, I didn't visit GC much.

What you ask is an excellent question. The word "what" in this context is a relative pronoun. Other relative pronouns are: who, whom, that, which, whoever, whatever. This is very important: a relative pronoun introduces a subordinate clause and, unlike a subordinate conjunction, plays a role as a noun in the clause. The relative pronoun may be the subject of the clause:
This is the man who wrote that interesting article.
I would like to thank whoever pruned the trees out front.
The relative pronoun may be the direct object of the verb of clause:
The man whom the police detained refuses to cooperate.
The novel The Great Gatsby, which I read for the first time this past year, was made into a famous movie in 2013.

Here's the OA of that GMAT Prep sentence
While digging in the Egyptian desert, paleontologists have found huge fossil bones from what appears to be the second most massive dinosaur that ever lived.
In the main clause of this sentence:
"paleontologists" is the main subject
"have found" is the main verb

The subordinate clause, a noun-clause or substantive clause, opens with the relative pronoun "what," which acts as the subject of the clause, the subject of the verb "appears." This entire substantive clause is the object of the preposition "from."

Does all this make sense?
Mike

The answer, shanks2020, lies in the inverted sentence structure at the tail-end of the sentence, particularly the singular the second most massive dinosaur. The comparison is of one type of dinosaur to another type (i.e. the most massive), irrespective of the individuals within that type. This is no different from saying, The tyrannosaurus rex was (not were) a fast-moving predator. It is understood that the sentence is talking about all T. rexes (or shall I say reges?), rather than a single specimen. If you straighten out choices (D) and (E), you get the following. I will underline the part in each sentence that concerns subject-verb agreement.

(D.2) What appears to be the second most massive dinosaur that ever lived [left] huge fossil bones that paleontologists have found while digging in the Egyptian desert.

(E.2) What appear to be the second most massive dinosaur that ever lived [left] huge fossil bones that paleontologists have found while digging in the Egyptian desert.

The problem with (E) should now be clear. The preposition from in both original answer choices serves as a cue that a subject, a noun of some sort, is about to follow. That subject, the dinosaur at its base, takes a singular verb agreement.

I hope that helps. If you have further questions, just let me know. Thank you for calling my attention to the question.

- Andrew

Hi AndrewN

Thanks for the reply. My query was typically on the consideraton of a specie as plural when we consider them as a whole.
So should it be taken as a observation? That when we talk of a whole class(specie) here we would use singular verb?

While digging in the Egyptian desert, huge fossil bones have been found by paleontologists, which appears to have been the second most massive dinosaur that ever lived.


A. huge fossil bones have been found by paleontologists, which appears to have been

B. huge fossil bones have been found by paleontologists, which appear to be from

C. it appears that paleontologists have found huge fossil bones that are from

D. paleontologists have found huge fossil bones from what appears to be

E. paleontologists have found huge fossil bones, which are from what appear to be