This play starts from the 1-3-1 set. This is triple option play, or "3". Also read Motion Offense.
First Option:(Diagram A) O1 at the point, passes to O2, and cuts around O4's screen. O2 passes to O1 for the lay-up if O1 is open. O4 seals the screened defender for inside position.
Second Option:(Diagram B) If O1 is not open (defense switched the screen), he/she clears out and cuts around O5's screen. At the same time, O4 (who should have inside position after the sealing on the screen) breaks to the hoop. O2 passes to O4 for the lay-up, if O4 is open.
O3 swings out to the point for two reasons: to protect against the opponent's fast break, and for the outlet pass for the next option.
Third Option:(Diagram C) If O4 is not open, he/she moves to the ball-side low block position to post up. O2 can still try to pass to O4 who can make a post move. O5 flashes to the ball-side elbow.
If O4 or O5 are not open, O2 reverses the ball back to O3 and then to O1 (or skip passes from O2 to O1). Now O4 moves over and posts-up on the ball-side block, while O5 moves to the ball-side elbow.
O1 can take the outside shot, or can pass inside to either O5 or O4.
There are actually a number of other options. O2 or O3 could take the outside shot if open. Once O1 cuts around O5's screen, O5 cuts to the high-post (free throw line) and could receive the pass from O2, O3, or O1. O5 could then shoot, drive or pass off to a wing, or down low to O4 (a "hi-lo" option).