The correct option is A BC and QR
If ΔABC∼ΔPQR, then AB and PQ are the corresponding sides, BC and QR are the corresponding sides, AC and PR are the corresponding sides.
If we group them in pairs, they will be
AB and PQ
BC and QR
AC and PR
Note that the symbol ∼ is used to show the similarity of two figures and corresponding sides exist only for similar or congruent figures.