___[A.It B.There]is no possibility that he can win the first prize.

选B

there is no+名词
it is no+形容词

A It

A ,宾语从句。IT 为形式宾语前置

B
possibility是名词，当然用there be 句型
如果选A,就是
it is impossible...
两位楼上都错啦！！

是B 对比It is impossible that

B
用there be 句型，他获得一等奖是没有可能的