Express the Given Quantity in Terms of Sin X or Cos

Multiple Choice

Express the given quantity in terms of sin x or cos x.
- $$\sin \left( \frac { 7 \pi } { 2 } - x \right)$$

A) $- \cos x$
B) $- \cos x - \sin x$
C) $- \cos ( - x )$
D) $\cos x$