The value of $\tan 3A-\tan 2A-\tan A$ is equal to

Question

$\begin{array}{1 1}(A)\;\tan 3A\tan 2A\tan A\\(B)\;-\tan 3A\tan 2A\tan A\\(C)\;\tan A\tan 2A-\tan 2A\tan 3A-\tan 3A\tan A\\(D)\;\text{None of these}\end{array}$