Answer: D
The first option is incorrect because 56+angle 3=180 and when you solve it angle 3 equals 124 degrees, not 142 degrees
The second option is incorrect because 56+43+angle 1=180 (because all triangles add up to 180 degrees). When you solve that angle 1 equals 81 degrees, not 99 degrees
The third option is incorrect because angle 1+angle 2=180, and we already know angle 1 equals 81, so when you solve that angle 2 equals 99 degrees, not 137 degrees. So we know the last option is correct.
But if you want to make sure it's correct, you can always solve for angle 4. Angle 4+43=180 degrees, and when you solve it, angle 4 equals 137 degrees, and we know that option is correct.
Hope this helped you!
