云计算新课2-下列选项中哪个方法不是java.util.Collection接口所定义的( )：
Aint size()
Bboolean containsAll(Collection c)
Cboolean remove(Object obj)
Dadd(int index, Object obj)
Aint size()
Bboolean containsAll(Collection c)
Cboolean remove(Object obj)
Dadd(int index, Object obj)