Answer:
D. They are reflections of each other across the y-axis.
Explanation:
F(x) becomes g(x) the only difference is that x becomes negative x
(x,y) → (-x,y) reflection over the y-axis
If we had had
(x,y) → (x,-y) reflection over the x-axis
(x,y) → (y,x) reflection over the line x=y