Sentence Correction

66. Scientists have recently received permisiions to research embryonic stem cells, derived from blastocysts or early-stage embryos, that they believe to be capable of generating new cell growth and curing previously incurable ailments.

B. that they believe are capable
C. that they believe will be capable
D. believed as capable
E. believed to be capable

OA is A

sudipto wrote:66. Scientists have recently received permisiions to research embryonic stem cells, derived from blastocysts or early-stage embryos, that they believe to be capable of generating new cell growth and curing previously incurable ailments.

B. that they believe are capable
C. that they believe will be capable
D. believed as capable
E. believed to be capable

OA is A

A: uses correct idiom. Believe X to be Y. scientists believed stem cells to be capable of

B: believe X are Y wrong idiom

C: believe X will be Y wrong idiom

D: doesnt specify believed by whom. Believe X as Y wrong idiom

E: doesnt specify believed by whom

sudipto wrote:66. Scientists have recently received permisiions to research embryonic stem cells, derived from blastocysts or early-stage embryos, that they believe to be capable of generating new cell growth and curing previously incurable ailments.

B. that they believe are capable
C. that they believe will be capable
D. believed as capable
E. believed to be capable

OA is A

Is "that required" in A to give correct meaning?

Stumped

I selected E because I thought use of 'they' in option A is ambiguous - scientists or cells. If we see in the context of the question then, yes, cells can't believe and hence 'they' is referring to 'scientists'.

So, is it fine to use plural pronoun even if there are multiple plural nouns present, provided it's clear from the context?

extensive discussion here:

https://www.beatthegmat.com/subjunctive- ... 10240.html