Complete the Identity $\sin \theta \cos ^ { 3 } \theta + \sin ^ { 3 } \theta \cos \theta = ?$

Multiple Choice

Complete the identity.
- $\sin \theta \cos ^ { 3 } \theta + \sin ^ { 3 } \theta \cos \theta = ?$

A) $\frac { 1 } { 2 } \sin ( 2 \theta ) \cos ( 2 \theta )$
B) $\frac { 1 } { 2 } \sin ( 2 \theta )$
C) $\frac { 1 } { 4 } \sin ^ { 2 } ( 2 \theta )$
D) $\frac { 1 } { 6 } \sin ( 3 \theta ) \sin ( 2 \theta )$