Rewrite the Following as a Product of Trigonometric Functions $\cos 8 ^ { \circ } - \cos 24 ^ { \circ }$

Rewrite the following as a product of trigonometric functions.
- $\cos 8 ^ { \circ } - \cos 24 ^ { \circ }$

A) $- 2 \sin 16 ^ { \circ } \sin \left( - 8 ^ { \circ } \right)$
B) $- 2 \sin 16 ^ { \circ } \cos \left( - 8 ^ { \circ } \right)$
C) $- 2 \cos 16 ^ { \circ } \sin \left( - 8 ^ { \circ } \right)$
D) $- 2 \cos 16 ^ { \circ } \cos \left( - 8 ^ { \circ } \right)$