C.
if x one of the angles, then, the other angle is 3x - 2. Due to these angles are supplementary, you can write:
x + 3x - 2 = 180
by solving for x you obtain:
x + 3x - 2 = 180 simplify like terms left side
4x - 2 = 180 add 2 both sides and divide by 4 both sides
4x = 180 - 2
4x = 178
x = 178/4
x = 44.5
the other angle is then:
3x - 2 = 3(44.5) - 2 = 131.5
Hence, the two angles are 44.5° and 131.5°