Rewrite as a Single Expression $\theta$ )Cos(3 $\theta$ ) + Cos(7 $\theta$ )Sin(3 $\theta$

Multiple Choice

Rewrite as a single expression. sin(7 $\theta$ ) cos(3 $\theta$ ) + cos(7 $\theta$ ) sin(3 $\theta$ )

A) cos(10 $\theta$ )
B) cos(4 $\theta$ )
C) sin(10 $\theta$ )
D) sin(4 $\theta$ )