The figure below shows parallel lines cut by a transversal:

A pair of parallel lines is shown with arrowheads on each end. A transversal cuts through these two lines. An angle formed between the top parallel line and the transversal on the inner left side is marked 1. Another angle formed between the bottom parallel line and the transversal on the inner right side is marked 2.
Which statement is true about ∠1 and ∠2? (5 points)

a
∠1 and ∠2 are congruent because they are pair of adjacent angles.

b
∠1 and ∠2 are complementary because they are a pair of adjacent angles.

c
∠1 and ∠2 are congruent because they are a pair of alternate interior angles.

d
∠1 and ∠2 are complementary because they are pair of alternate interior angles.