If $r_{xy}$ between two variates $x$ and $y$ is 0.6 $ cov (x,y)=4.8\: \sigma_x^2=9$ then $\sigma_y$ is

Question

$\begin {array} {1 1} (A)\;\large\frac{8}{9} & \quad (B)\;\large\frac{5}{8} \\ (C)\;\large\frac{8}{3} & \quad (D)\;None \: of \: these \end {array}$