Complete the Sentence So the Result Is an Identity $\sin ( s + t )$

Multiple Choice

Complete the sentence so the result is an identity. Let x be any real number.
-Find $\sin ( s + t )$ given that $\cos s = - \frac { 12 } { 13 }$ , with $s$ in quadrant II, and $\sin t = \frac { 8 } { 17 }$ , with $t$ in quadrant II.

A) $\frac { 171 } { 221 }$
B) $- \frac { 171 } { 221 }$
C) ----
D) $- \frac { 21 } { 221 }$