Simplify the Expression $$- \sqrt { \frac { 81 } { 8 } }$$

Multiple Choice

Simplify the expression. Assume all variables represent positive real numbers.
- $$- \sqrt { \frac { 81 } { 8 } }$$

A) $- 9 \sqrt { 2 }$
B) $- \frac { 9 \sqrt { 2 } } { 4 }$
C) $- 8$
D) $- \frac { 9 \sqrt { 2 } } { 2 }$