Throw-in question; when can the thrower legally touch the ball again?

[RefLarry]

Thank you mbyron


4.35.2 SITUATION:
Thrower A1 inbounds the ball to A2. A2 immediately throws
the ball back to A1. When A1 touches the pass, he/she has: (a) both feet touching
inbounds; (b) one foot touching inbounds and one out of bounds; or (c) one
foot touching inbounds and the other not touching the floor. RULING: The ball
remains live in (a) and (c), but A1 has caused the ball to be out of bounds in (b).
(4-4-4)