---What do you think made Celia so happy?
--- a prize in the recent petition.
A. She won
B. Won
C. Winning
D. Because of winning
网友回答
A. She won
B. Won
(答案→)C. Winning
D. Because of winning
解析：句意：--你认为是什么让Celia这么高兴的？--在最近的比赛中得了一个大奖。这里是回答what…的问题，用动名词短语作主语， 答语后面省略了 made Celia so happy。选C。