Our present accountant is most ____ ; unlike the previous _____ incumbent, he has never made a mistake in all the years that he has worked for the firm.
A. asinine - diligent
B. unorthodox - heretical
C. dependable - assiduous
D. meticulous - unreliable
Meticulous: Extremely careful and precise.
Unreliable: Marked by or exhibiting a lack of reliability.