The fraction X of male runners and the fraction Y of female runners who compete in marathon races are described by the joint density functionf(x,y)=8xy,0yx1

. Find the correct options in the following?

A.E(X Y) = 4/9

B.E(X) = 4/5

C.E(Y) = 4/15

D.cov(X,Y) = 4/225.