Use an Identity to Write the Expression as a Single $1 - 2 \sin ^ { 2 } 2 x$

Multiple Choice

Use an identity to write the expression as a single trigonometric function or as a single number.
- $1 - 2 \sin ^ { 2 } 2 x$

A) $\cos 4 \mathrm { x }$
B) $\frac { 1 } { 2 } \sin 16 x$
C) $\cos 8 x$
D) $2 \sin 4 x$