—What are you going to do in the summer vacation?
—I ________ a volunteer in the hospital.
A . was B . am C . will be
C
【详解】句意: —— 暑假你打算做什么? —— 我将成为医院的志愿者。
考查时态。根据 “What are you going to do in the summer vacation” 可知此处描述将来的动作,用一般将来时 will do 。故选 C 。