Question

I need help on this question

Answer 1

A) always is your answer

Think of it as congruent:

In picture two, it shows that m∠c + m∠d = 180°, m∠d + m∠f = 180° ∴ ∠c ≅ ∠f.

hope this helps

Picture 1: Alternate interior angles

Picture 2: Alternate interior angles