Ben uses a compass and a straightedge to bisect angle PQR, as shown below: The figure shows two rays QP and QR having a common end point Q. An arc drawn from Q cuts the ray QP at A and the ray QR at B.
Which statement best explains why Ben uses the same width to draw arcs from A and B which intersect at S? (6 points)

BQ = BS when ∠AQS ≅ BQS.

AQ = AS when ∠AQS ≅ BQS.

∠AQS ≅ BQS when AS = BS and AQ = BQ.

∠AQS ≅ BQS when AS = BQ and BS = AQ.