What Is the Variance of the Expected Returns on This

Multiple Choice

What is the variance of the expected returns on this stock?
$\begin{array}{lrr}\text { State of the Economy } & \text { Probability of } & \text { Rate of Return if } \\& \text { State of Economy } & \text { state occurs }\\\text { Boom } & .30& 20\% \\\text { Normal } & .70 &10 \%\end{array}$

A) 18.75%
B) 21.00%
C) 31.53%
D) 48.97%
E) 50.03%