Angles 1, 3, and 4 make up a straight line.
Thus, 3x + 90 + 3x - 6 = 180 (angle sum of straight line)
6x - 6 = 90
6x = 96
x = 16
Now angle 1 becomes 3(16) = 48
Angle 1, 2, and 3 also make up a straight line.
Thus, angle 2 + 48 + 90 = 180
angle 2 + 138 = 180
angle 2, therefore, becomes 42. In essence, (A)