Shewastoldtogivetheawardtowhomsheeverthoughthadcontributedmosttothewelfareofthestudentbody.

参考答案:

B

结构应用与习惯搭配, give the award to sb.是习惯搭配；而此处的sb.虽是介词to的宾语，却是后面从句had contributed most to the welfare of the student body 的主语，所以只有 B 为答案。