For the Given Functions F and G, Find the Composition $f ( x ) = x ^ { 2 } + 3 x ; g ( x ) = \sqrt { x } \quad$

Multiple Choice

For the given functions f and g, find the composition.
- $f ( x ) = x ^ { 2 } + 3 x ; g ( x ) = \sqrt { x } \quad$ Find $( g \circ f ) ( 6 )$

A) $2 \sqrt { 3 }$
B) $3 \sqrt { 5 }$
C) $\sqrt { 39 }$
D) $3 \sqrt { 6 }$