Use the Functions Given By $f ( x ) = x + 4$

Use the functions given by $f ( x ) = x + 4$ and $g ( x ) = 2 x - 6$ to find the composition of functions $g ^ { - 1 } \circ f ^ { - 1 }$

A) $\frac { x - 2 } { 2 }$
B) $\frac { x + 2 } { - 2 }$
C) $\frac { x - 2 } { - 2 }$
D) $\frac { - ( x + 2 ) } { 2 }$
E) $\frac { x + 2 } { 2 }$