The Expression $P(A \cap B)=P(A) P(B \mid A)$ Is Valid If
A)

Multiple Choice

The expression $P(A \cap B) =P(A) P(B \mid A)$ is valid if

A) $A$ and $B$ are independent.
B) $A$ and $B$ are mutually exclusive.
C) only if $A$ equals $B^{\prime}$ .
D) for any events $A$ and $B$ .