IW on pass play that is intercepted w/flag

[PaulJak]

Since you've got a foul A has to decide if they want to accept or decline the penalty. Clearly they will accept the DPI foul in this case. Since there is an accepted penalty you can ignore the IW.

Where this gets a little more interesting is if there was no flag on the play.

If there is no flag, B gets hosed. Since A was in team possession at the time of the IW they would get to choose. Since the ball was loose at the time they can take the ball at the end of the last run (and the last run was the quarterback dropping back to throw) or they can replay the down. In this case they'd choose to replay the down and B can't retain possesion.

I don't have my book with me so this is what I would do on the field, am I correct about team possession determining whose option or does it go all the way back to the team that snapped the ball. In other words, if the IW came after B had completed the interception, would it be B's choice.