Lines m and n are cut by a transversal l.

Which angle pair relationship should be used to prove lines m and n are parallel?

Angles 1 and 5 are congruent corresponding angles.
Angles 2 and 8 are supplementary alternate exterior angles.
Angles 3 and 6 are congruent with same-side interior angles.
Angles 4 and 6 are supplementary alternate interior angles.