D
be to do sth表示将要做某事,be doing表示正在做.而原句意思应该是即将颁奖给学生.例句：I don't know what is to be done next. 不知下一步该怎么做.
用is,这是属于主谓一致原则中“就近一致”原则,适用于"or, either... or, neither...nor, not only... but also"等句型,也就是说谓语要和后面的主语保持一致.
下面是几个例句：
You or Tom is going on business.
Neither you nor I am wrong.
Not only the students but also the teacher wishes for a holiday
希望能有所帮助:)