Simplify $(x^{4n-m})\large(\frac{1}{x^3})^{m+n}$

Question

$\begin{array}{1 1} (a)\;x^{4m-n} \\ (b)\; x^{n-4m} \\ (c)\; x^{4n-m} \\ (d)\; x^{m-4n} \end{array}$