Question

As researchers continue to probe the highly expressive vocal and postural language of wolves, their close resemblance to dogs has become ever more striking.
(A) their close resemblance to dogs has become
(B) the closeness of their resemblance to dogs has become
(C) the close resemblance between them and dogs has become
(D) the close resemblance between wolves and dogs becomes
(E) the close resemblance of wolves with dogs becomes
___

Answer 1

The use of the pronoun in A and C is highly awkward, as it could refer to either "researchers" or "wolves." "Resemblance with" is an incorrect idiom, so we rule out E. B has a less ambiguous pronoun than A or C but for the "closeness" to be striking rather than the "resemblance" is extremely heavy.

Hence the only option remaining is D