I really need the help please and thank you

Answer:
Answer is D.
Step-by-step explanation:
Let the inverse be m:
[tex]{ \sf{m = \sqrt{x} - 8 }} \\ { \sf{m + 8 = \sqrt{x} }} \\ { \sf{x = {(m + 8)}^{2} }} \\ { \bf{f {}^{ - 1} (x) = {(x + 8)}^{2} }}[/tex]
Domain:
[tex]{ \sf{x \geqslant - 8}}[/tex]