For $a$ bivariate distribution $(x,y)$ if $ \Sigma x = 50 \: \Sigma y = 60 \: \Sigma xy = 350 \: \overline x = 5\: \overline y = 6 \: var \: x=4\: var \: y=9\: then \: r(x,y)=$

Question

$\begin {array} {1 1} (A)\;\large\frac{5}{6} & \quad (B)\;\large\frac{5}{36} \\ (C)\;\large\frac{11}{3} & \quad (D)\;\large\frac{11}{18} \end {array}$