It’s C i believe Angle 3 and 6 both equal 90 degrees. angle 1 is collinear with 6 and 5. Those three angles (1,6, and 5) add up to 180 degrees. If you subtract your angle 6(90) from 180 , you get 90 , then u subtract ur angle one(55) from 90 and get 35 degrees. I hope this makes sense, it’s harder to explain online
