If $8 \tan A = 15$ then $\sin A - \cos A$ is ___

Question

$\begin{array}{1 1}(A) \; \large\frac{7}{17} \\(B)\;\large\frac{7}{18} \\(C)\;\large\frac{7}{15} \\(D)\;\large\frac{7}{12} \end{array}$