Evaluate Without Using a Calculator, Leaving the Answers in Exact $\sin \frac { 3 \pi } { 4 }$

Multiple Choice

Evaluate without using a calculator, leaving the answers in exact form. $\sin \frac { 3 \pi } { 4 }$

A) $\frac { \sqrt { 2 } } { 2 }$
B) $\frac { 1 } { 2 }$
C) 1
D) 0
E) $\frac { 3 } { 2 }$