Last play penalty question and enforcement

[bisonlj]

When giving the options to B, I would probably be as thorough as possible:

If you accept A's penalty, we'll have a double foul and replay the down for A
If you decline B's penalty, you'll get the ball at the A25 (assume 10-yard illegal block) IF A accepts your penalty. If they decline your penalty, the game will be over.

You don't let A decide before B decides but you let B know the full impact of their decisions.

[With_Two_Flakes]

Interesting question. Never considered this sort of situation before.

Would it be the same rationale under NCAA Rules?

[Texas Aggie]

Putting aside that 6 on the line is no longer an NCAA foul (we'll just substitute it with 5 in the backfield, since that isn't the issue here), the NCAA ruling is pretty much the same. The way to approach this is to tell B that they have 2 ultimate choices: either there's an untimed down with A keeping the ball (offsetting fouls) or the quarter has ended (declined penalties, making what happened stand). If they want to know why, I'll explain, but no rational A coach is going to let B take an untimed offensive play when they can avoid it, thus the question of whether to accept or decline (for A) is obvious.