Thanks a lot Rich Your Explanation makes things clear.

Thomas Eakins' powerful style and his choices of subject--the advances in modern surgery, the discipline of sport, the strains of individuals in tension with society or even with themselves--was as disturbing to his own time as it is compelling for ours.

(A) was as disturbing to his own time as it is
(B) were as disturbing to his own time as they are
(C) has been as disturbing in his own time as they are
(D) had been as disturbing in his own time as it was
(E) have been as disturbing in his own time as

A COMPOUND subject is composed of two nouns connected by and:
X and Y.
Generally, a compound subject requires a PLURAL verb.
Here, the subject of the sentence is Thomas Eakins' powerful style AND his choices of subject.
Since the subject is compound, the verbs must be plural.
This would be the case even if choices were replaced with choice.

In A and C, was (singular) and has (singular) do not agree with Thomas Eakins' powerful style and his choices (plural). Eliminate A and C.

In D, it (singular) does not agree with Thomas Eakins' powerful style and his choices (plural). Eliminate D.

In E, his own time implies a definite time in the past. Thus, have been (present perfect) is incorrect. The regular past tense is needed: Thomas Eakins' powerful style and his choices...WERE as disturbing to HIS OWN TIME. Eliminate E.

The correct answer is B.

(A) was as disturbing to his own time as it is
(B) were as disturbing to his own time as they are - correct
(C) has been as disturbing in his own time as they are
(D) had been as disturbing in his own time as it was
(E) have been as disturbing in his own time as

What was/were disturbing?? Powerful style and Choices of subject. So we need a plural verb. So choices A,C and D are eliminated. In choice E there is no reference what is compelling for ours.


So the answer is B.