Answer: A. Prove that QR≅QR by the reflexive property.
Step-by-step explanation:
ASA postulate says that if two angles and the included side of a triangle are congruent to two angles and the included side of other triangle then the triangles are said to be congruent.
In the given triangles ΔPQR and ΔSQR
∠PQR ≅∠SQR {given}
∠QRP ≅ ∠QRS {given}
In the figure , the included side of ∠PQR and ∠QRP= QR
The included side of ∠SQR and ∠QRS =OR
So we need to probe QR≅QR by Reflexive property, to prove triangles ΔPQR and ΔSQR are congruent.