Use the Product-To-Sum Formula to Write the Given Product as a Sum

Multiple Choice

Use the product-to-sum formula to write the given product as a sum or difference.
$8 \sin \frac { \pi } { 8 } \sin \frac { \pi } { 8 }$

A) $4 \sin \frac { \pi } { 16 }$
B) $4 - 4 \cos \frac { \pi } { 4 }$
C) $4 + 4 \cos \frac { \pi } { 16 }$
D) $- 4 \sin \frac { \pi } { 16 }$
E) $4 \sin \frac { \pi } { 8 } + 4 \cos \frac { \pi } { 8 }$