If $\tan\alpha=\large\frac{m}{m+1}$$,\tan \beta=\large\frac{1}{2m+1}$,then $\alpha+\beta$ is equal to

Question

$\begin{array}{1 1}(A)\;\large\frac{\pi}{2}&(B)\;\large\frac{\pi}{3}\\(C)\;\large\frac{\pi}{6}&(D)\;\large\frac{\pi}{4}\end{array}$