Simplify the Radical Expression $$\sqrt { 405 x ^ { 2 } }$$

Multiple Choice

Simplify the radical expression. Assume all variables represent nonnegative real numbers.
- $$\sqrt { 405 x ^ { 2 } }$$

A) $405 x$
B) $9 \sqrt { 5 x }$
C) $9 x$
D) $9 x \sqrt { 5 }$