PLEASE HELP ME i need help

Answer:
C.
[tex] \sqrt{5x - 7} + 13[/tex]
Step-by-step explanation:
When facing a problem like this think of the x in G(x) as the variable (which it essentialy is). So if you replace the x in G(x) with F(x) you get
[tex]g(f(x)) = \sqrt{f(x)} + 13[/tex]
and if you substitute F(x):
[tex]g(f(x)) = \sqrt{f(x)} + 13 = \sqrt{5x - 7} + 13[/tex]