10. What is the covariance of returns between stocks a and b? expected return of A is 50% and b's expected return = 10%.

a. none of the listed items is correct

b. 0.0433

c. 0

d. 0.05

e. 0.0933

\begin{tabular}{|l|l|l|} \hline Year & Return A & Return B \\ \hline 2017 & 80% & 35% \\ \hline 2016 & 40% & 15% \\ \hline 2015 & 30% & 20% \\ \hline \end{tabular}