He is the only one of the students in our grade 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：考查定语从句。本定语从句的先行词是the only one，故使用单数形式，排除BC项。根据本句的时间状语for three years说明使用完成时。故D正确。句意：他是我们年级的学生中唯一的一个获得奖学金的人。故D正确。