Good One

[JC]

If the buzzer sounds before the ball enters the basket, no points are scored. (The try was over when the ball hit the floor, so the period is over when the buzzer sounds).

If the buzzer sounds after the ball enters the basket, 2 points are scored for A. The ball entered before time expired, so the ball is live and 2 points are scored. Not 3, because the 3 point try ended when it was obviously not successful (hitting the floor would be my first clue it wasn't successful).

J.C.