If $b_{yx} = \large\frac{1}{2}$ and $b_{xy} = \large\frac{2}{3}$ and $ \theta$ is the acute angle between the two regression lines then $ \tan \theta$ =

Question

$\begin {array} {1 1} (A)\;\large\frac{2}{7} & \quad (B)\;\large\frac{4}{7} \\ (C)\;\large\frac{6}{7} & \quad (D)\;None \: of \: these \end {array}$