Use the Formula for the Cosine of the Difference of Two

Multiple Choice

Use the Formula for the Cosine of the Difference of Two Angles
- $\cos \left( 160 ^ { \circ } \right) \cos \left( 40 ^ { \circ } \right) + \sin \left( 160 ^ { \circ } \right) \sin \left( 40 ^ { \circ } \right)$

A) $\cos \left( 120 ^ { \circ } \right)$
B) $\cos \left( 210 ^ { \circ } \right)$
C) $\cos \left( 190 ^ { \circ } \right)$
D) $\cos \left( 220 ^ { \circ } \right)$