Sentence Correction

Paleontologists believe that fragments of a primate jawbone unearthed in Burma and estimated at 40 to 44 million years old provide evidence of a crucial step along the evolutionary path that led to human beings.

(A) at 40 to 44 million years old provide evidence of

(B) as being 40 to 44 million years old provides evidence of

(C) that it is 40 to 44 million years old provides evidence of what was

(D) to be 40 to 44 million years old provide evidence of

(E) as 40 to 44 million years old provides evidence of what was

Option D is the best choice here because it correctly follows estimated with to be.
The other choices have Idiom prblem, when used in conjunction with estimated.

A - incorrect - unidiomatic

B, C, E - incorrect - all mismatch the singular verb "provides" with its plural subject "fragments" .
Further in C and E, what was is unnecessary and wordy.

IMO: D

The Jock wrote:Option D is the best choice here because it correctly follows estimated with to be.
The other choices have Idiom prblem, when used in conjunction with estimated.

A - incorrect - unidiomatic

B, C, E - incorrect - all mismatch the singular verb "provides" with its plural subject "fragments" .
Further in C and E, what was is unnecessary and wordy.

What is estimated with to be?

Question: What is estimated with to be?
it is estimated to be, the correct idiom here.[/quote]