He is the only one of the students who a winner of scholarship for three years.
A. is
B. are
C. have been
D. has been
网友回答
A. is
B. are
C. have been
(答案→)D. has been
解析：根据for three years，故用现在完成时，且这个定语从句的先行词是the only one of the students，故谓语动词用单数，所以选D。