Provide an Appropriate Response $f ( x ) = a ^ { x }$

Multiple Choice

Provide an appropriate response.
-Give an equation of the form $f ( x ) = a ^ { x }$ to define the exponential function whose graph contains the point $( 2,16 )$ . Assume that $a > 0$ .

A) $f ( x ) = 16 ^ { x }$
B) $f ( x ) = 8 ^ { x }$
C) $f ( x ) = 4 ^ { x }$
D) $f ( x ) = 256 ^ { x }$