Answer: Angles B and D (second choice)
Step-by-step explanation:
Erase the line from angle C to angle A. You'll be left with only one transversal. This transversal forms angles B and D, which are alternate interior angles. They are inside the parallel lines, so that's what makes them interior. They are also on alternating sides of the transversal line. Alternate interior angles are congruent when we have parallel lines like this.
Side note: Another pair of alternate interior angles would be angle A and angle E.