单选题

熵、条件熵、联合熵、互信息之间的关系错误的是？

Question

A. I(X,Y) = H(Y) – H(Y|X)

B. I(X,Y) = H(X) – H(X|Y)

C. H(X|Y) <= H(X)

D. H(X|Y) <= H(Y)