Neither his financial patron
or Copernicus himself were expecting the societal backlash resulting from him denouncing the Earth-centered Ptolemaic model of the universe.
(A)
or Copernicus himself were expecting the societal backlash resulting from him (Neither/Nor is the idiomatic sentence) INCORRECT
(B)
or Copernicus himself was expecting the societal backlash resulting from him(Neither/Nor is the idiomatic sentence) INCORRECT
(C)
nor Copernicus himself was expecting the societal backlash resulting from his (CORRECT)
(D)
nor Copernicus
were expecting the societal backlash resulting from him (Subject after or is singular, were is wrong) INCORRECT
(E)
nor Copernicus
was expecting the societal backlash resulting from
himself (Himself denouncing the Earth-Centered model? the guy was model? nope he denounced something. Himself before denouncing is murky) INCORRECT
Answer is C