Use Reference Angles to Find the Exact Value of the Expression

Multiple Choice

Use reference angles to find the exact value of the expression. Do not use a calculator.
- $\sin 855 ^ { \circ }$

A) $\frac { \sqrt { 2 } } { 2 }$
B) $\frac { 1 } { 2 }$
C) $- \frac { 1 } { 2 }$
D) $- \frac { \sqrt { 2 } } { 2 }$