If $x=2^{2n}$,then the value of $8.x^{\Large\frac{3}{2n}}-8.x^{-\Large\frac{3}{2n}}$ is __

Question

$\begin{array}{1 1}(A) \; 32\\(B)\;63\\(C)\;21 \\(D)\;64 \end{array}$