In △PQR and △XYZ, it is given that ∠P=∠X, ∠Q=∠Y and PQ=XY. Which of the following correctly justifies whether the two triangles are congruent?
a) They are congruent by SAS criterion.
b) They are congruent by AAS criterion.
c) They are congruent by ASA criterion.
d) Congruence cannot be proved because PQ is not the included side.