The question has an error because the letter g does not make sense in the context.
I will assume that the g is really the number 9.
In that case, the equation to solve would be:

You can solve for x following these steps:
1) make

=>

2) Given that the basis are equal the exponents have to be equal =>
2x = 2(3x - 4)
3) Solve:
2x = 6x - 8
6x - 2x = 8
4x = 8
x = 8/4
x = 2 which is the option B) which leads me to think that a 9 instead of g in the equation should be right.
Under that assumption, the answer is the option B) x = 2.