$\begin{align*} \int \frac{\sin^6x}{\cos^8 x}dx \end{align*}$ is equal to :

Question

( A ) $\frac{\tan 7 x}{7} + c$
( B ) $\sec^7 x+c$
( C ) $\tan 7x + c$
( D ) $\frac{\tan^7 x}{7} + c$