Answer: B) Linear pair postulate
Explanation:
As the name implies, "linear pair" means the two angles combine to form a straight line of 180 degrees. Think of gluing the angles together.
As an example, let's say angle 1 was 50 degrees and angle 4 is 130 degrees. They combine to 50+130 = 180 which is a straight angle. I recommend using a protractor to help draw these angles.
