Scenario 1: B accepts the Illegal Formation. A accepts the IBW. Double foul, offsetting penalties, A's ball, replay the down.
Scenario 2: B accepts the penalty. A declines the penalty. Five yards back from the LOS, A's ball, replay the down.
Scenario 3: B declines the penalty. A accepts the penalty. Ten yards back from the spot of the foul, B's ball, 1st & 10.
Scenario 4: B declines the penalty. A declines the penalty. Touchback, A's ball, 1st & 10 at their own 20 yd. line.