If $\tan \theta=\large\frac{1}{2}$ and $\tan\phi=\large\frac{1}{3}$,then the value of $\theta+\phi$ is

Question

$\begin{array}{1 1}(A)\;\large\frac{\pi}{6}&(B)\;\pi\\(C)\;0&(D)\;\large\frac{\pi}{4}\end{array} $