The answer is option C when your doing inverse functions you need to switch the variables but substituting x with y. So, the equation would look like this:
y = 3x + 4 ---> x = 3y + 4
x = 3y + 4
Subtract 4 on both sides:
Then divide 3 on both sides: " [tex] \frac{x - 4}{3} =y [/tex] or option C "