Mei draws three pairs of parallel lines that are each intersected by a third line. In each figure, she measures a pair of angles.
What is a reasonable conjecture for Mei to make by recognizing a pattern and using inductive reasoning?
When a pair of parallel lines are intersected by a third line, the alternate interior angles are acute.
When a pair of parallel lines are intersected by a third line, all of the angles formed are obtuse.
When a pair of parallel lines are intersected by a third line, all of the angles formed are congruent.
When a pair of parallel lines are intersected by a third line, the alternate interior angles are congruent.