Find the Domain Of $f \circ g$ Where $f ( x ) = \sqrt { x - 7 }$

Multiple Choice

Find the domain of $f \circ g$ where $f ( x ) = \sqrt { x - 7 }$ and $g ( x ) = x + 5$ .

A) $[ - 5 , \infty )$
B) $[ 0 , \infty )$
C) $[ 7 , \infty )$
D) $[ - 2 , \infty )$
E) $[ 2 , \infty )$