illegal/legal dribble

[OHBBREF]

Team A inbounds the ball from mid court into their back court. A1 with the ball being pressured lightly by B1. Team A does the clear out for A1 to bring the ball up against the pressure alone.
B1 tightens the pressure quickly A1 losses the dribble with no one to help him/her in the back court.
A1 throws the ball;
a) against the back board and lets it hit the ground and begins dribbling...
b) throws the ball off the referees leg and begins dribbling...
c) throws the ball off the opponent and begins dribbling.

What do you have?