The left side shows (-22+3x) all over (3x+7). Division is happening when comparing the two expressions (-22+3x) and (3x+7). To undo that division, we multiply both sides by 3x+7. That effectively moves the 3x+7 over to the right side. It cancels out the version on the left side. This will get rid of the fraction.
Answer: Choice A
Side note: you have the correct solution for x. To check your answer, replace every copy of x with -12 and simplify
(-22+3x)/(3x+7) = 2
(-22+3*(-12))/(3*(-12)+7) = 2
(-22-36)/(-36+7) = 2
(-58)/(-29) = 2
2 = 2
The answer is confirmed