Find the Function Value $f ( x ) = 4 x$

Multiple Choice

Find the function value. If the result is irrational, round your answer to the nearest thousandth.
-Let $f ( x ) = 4 x$ . Find $f \left( \frac { 5 } { 2 } \right)$ .

A) 10
B) 32
C) 512
D) $1.741$