You are given that PS ≅ RS as indicated by the single has mark.
You are given that ∠PST ≅ ∠RST as indicated by the single arc.
You know the segment ST is congruent to itself by the reflexive property.
That is, you have two congruent sides and the angle between them, so you can claim the triangles are congruent by the SAS postulate.
Selection C is appropriate.
