Evaluate the Radical Function at the Given Value of the Variable

Multiple Choice

Evaluate the radical function at the given value of the variable.
- $$f ( x ) = \sqrt { 2 - 4 x }$$

A) $\left( - \infty , \frac { 1 } { 2 } \right)$
B) $\left( - \infty , \frac { 1 } { 2 } \right]$
C) $\left[ - \frac { 1 } { 2 } , \infty \right)$
D) $\left[ \frac { 1 } { 2 } , \infty \right)$