Determine Whether the Function Has an Inverse Function $f ( x ) = \sqrt { 7 x + 8 }$

Multiple Choice

Determine whether the function has an inverse function.If it does, find the inverse function.
$f ( x ) = \sqrt { 7 x + 8 }$

A) $f ^ { - 1 } ( x ) = - \frac { x ^ { 2 } + 8 } { 7 }$
B) $f ^ { - 1 } ( x ) = - \frac { x ^ { 2 } - 8 } { 7 }$
C) $f ^ { - 1 } ( x ) = \frac { x ^ { 2 } - 8 } { 7 }$
D) $f ^ { - 1 } ( x ) = \frac { x ^ { 2 } + 8 } { 7 }$
E) No Inverse