Hey there :)
f ( x ) is y
So here, f ( x ) = x - 2
Which is y = x - 2
To find an inverse of a function, just exchange x and y places
And solve for y
x = y - 2
Take 2 to the other side to isolate y
[ You do addition when you see subtraction ]
x + 2 = y
Your answer will be Option D) f⁻¹ ( x ) = x + 2
The picture I have attached might help you