$\displaystyle\lim_{x \to \frac{\pi}{2}} \frac{\cot x - \cos x}{(\pi - 2 x)^3}$ equals

Question

( A ) $\frac{1}{24}$
( B ) $\frac{1}{16}$
( C ) $\frac{1}{4}$
( D ) $\frac{1}{8}$