Chris wrote an equation and the first step of his solution process, as shown.

6 = 12 − 6x
-6 = -6x

Which math operation did Chris apply in his first step?
A) He divided 16 by 4.
B) He added 12 to each side of the equation.
C) He divided each side of the equation by 4.
D) He subtracted 12 from each side of the equation.
Please help me