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.
Thomas Eakins’ powerful style and his choices of subject are plural and must direct plural verbs.
(A) was as disturbing to his own time as it is- was and it is singular, but Thomas Eakins’ powerful style and his choices of subject are plural.
(B) were as disturbing to his own time as they are- >Okay. Let's keep it.
(C) has been as disturbing in his own time as they are- > has is singular, but Thomas Eakins’ powerful style and his choices of subject are plural.
(D) had been as disturbing in his own time as it was-> it is singular, but Thomas Eakins’ powerful style and his choices of subject are plural.
(E) have been as disturbing in his own time as-> Pronoun missed in last.
So, I think B.