Given F(x) and G(x), Find the Indicated Composition and State $f ( x ) = 5 \sqrt { x + 3 }$

Multiple Choice

Given f(x) and g(x) , find the indicated composition and state its domain.
-For $f ( x ) = 5 \sqrt { x + 3 }$ and $g ( x ) = 2 x + 9$ , what is the domain of $g \circ f$ ?

A) $[ - 12 , \infty )$
B) $( - 3 , \infty )$
C) $( - \infty , \infty )$
D) $[ - 3 , \infty )$