$cov (x,y) $ if $ \Sigma x = 55\: \Sigma y = 82\: \Sigma xy = 565\: n=8$ is

Question

$\begin {array} {1 1} (A)\;0.16 & \quad (B)\;0.7 \\ (C)\;7 & \quad (D)\;6 \end {array}$