The inverse functions have a property that the composition of two inverse functions always results is x.
From the given options, only the pair given in option B result in the composition equal to x.
[tex]F(x)= \frac{12}{x}-18 \\ \\
G(x)= \frac{12}{x+18} \\ \\
F(G(x))= \frac{12}{ \frac{12}{x+18} }-18 \\ \\
F(G(x))= \frac{12(x+18)}{12}-18 \\ \\
F(G(x))=x+18-18=x [/tex]
This proves, F(x) and G(x) are inverse of each other.
So the answer to this question is Option B