The film I saw yesterday is the best one__________I've ever seen

The film I saw yesterday is the best one__________I've ever seen.
A、Which
B、that
C、what
D、of which
【正确答案】：B
【题目解析】：此题考查定语从句的用法。当先行词被形容词最高级修饰时，关系代词只能用that。