单选题

下表是X={1,2,3}，Y={1,2,3}的概率矩阵。以下说法不正确的是：

Question

A.

X and Y are independent

B.

The covariance of X,Y is non-zero

C.

The probability Y=3 conditional on X=1 is 10%

D.

The unconditional probability that X=2 is 50%