End of game sitch

Team A is down 4 points with less than 15 seconds on the game clock. A2 scores on a 3 point try... Team A is now down by 1. Team B delays in picking up the ball, the official begins his 5 second count. B1 sees the count, picks up the ball & tosses it to the official.
What would you do?

Any casebook play provided would be greatly appreciated. Thanks!