Simplify the Radical Expression $$\sqrt { - \frac { 529 } { 441 } }$$

Multiple Choice

Simplify the radical expression. Indicate if the expression is not a real number.
- $$\sqrt { - \frac { 529 } { 441 } }$$

A) $\frac { 23 } { 21 }$
B) $- \frac { 23 } { 21 }$
C) $- \frac { 6 } { 5 }$
D) Not a real number