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 $( 3,216 )$ . Assume that a $> 0$ .

A) $f ( x ) = 729^ x$
B) $f ( x ) = 46,656 ^ { x }$
C) $f ( x ) = 6 ^ { x }$
D) $f ( x ) = 18 ^ { x }$