Look at this system of equations. How can the system be changed so that the two equations have equal x-coefficients?
3x + 2y = 12
6x + 3y = 21
A. Multiply both sides of the top equation by 2
B. Divide both sides of the top equation by 2
C. Multiply both sides of the top equation by 3
D. Divide both sides of the top equation by 3