Write the Expression as the Sine, Cosine, or Tangent of an Angle

Multiple Choice

Write the expression as the sine, cosine, or tangent of an angle.
- $\sin 4 x \cos x - \cos 4 x \sin x$

A) $\sin 5 x$
B) $\sin 3 x$
C) $\cos 3 x$
D) $\cos 5 x$