Given: RT || SP, RQ ≅ QP, RP bisects ST at Q Prove: ΔRQT ≅ ΔPQS

Triangles R Q T and P Q S are connected at point Q. Lines R T and S P are parallel. The lengths of lines R Q and Q P are congruent.
Tamir is working to prove the triangles congruent using SAS. After stating the given information, he states that TQ ≅ QS by the definition of segment bisector. Now he wants to state that ∠RQT ≅ ∠PQS. Which reason should he use?

alternate interior angles theorem
corresponding angles theorem
linear pair postulate
vertical angles theorem