((I forgot how to do find inverse functions and this is important))

Find the inverse function of g(x) = 2x + 4.
A) g^(-1)(x) = 4x + 2
B) g^(-1)(x) = 2x + 1/2
C) g^(-1)(x) = 1/2x - 2
D) g^(-1)(x) = 2x - 4

I *think* it might be C but I'm not sure.

" I *think* it might be C but I'm not sure."

Unacceptable in mathematics. If you know your material there is no such thing as "I'm not sure"

Your lessons, text or notes will show the following steps to find the inverse:

let y = 2x+4
step1: interchange the x and y variables
-----> x = 2y + 4
step2: solve this new equation for y
2y+4 = x
2y = x - 4
y = (x-4)/2 or y = (1/2)x - 2

another way to look at it:
y = 2x + 4 , the first thing you do is multiply your given number by 2, then add 4

the inverse of multiplication is division, the inverse of addition is subtraction, so we reverse the process (inverse)

the first thing I do is subtract 4 from the given x, than I divide it by 2