Let $f ( x ) = \sqrt { x } , g ( x ) = x + 2$

Multiple Choice

Let $f ( x ) = \sqrt { x } , g ( x ) = x + 2$ . Find the composite function which expresses the given correspondence correctly.
$\sqrt [ 4 ] { x }$

A) $\quad ( f \circ f ) ( x )$
B) $\quad ( g \circ f ) ( x )$
C) $\quad ( g \circ g ) ( x )$
D) $\quad ( f \circ g ) ( x )$
E) none of the above