The correct answer to this question is option 2 or B - (2x).
The left side is equal to 8x+2 (2x1=2 2x=2x 2x+6x=8x) so the right side needs to be equal to 8x+2 too. The 2 is already there, but you need to multiply 4 by something to get 8x. Option 1 or A would not work because it would only create 4x. Option 3 or C would not work because it would create 12x which is too high.
