Ok I've got it, just like if A would've been charged with holding behind the basic spot.

They would be insane to accept the penalty, because it's so easy for team A to give up a safety on the repeated down if they want to.

As to the business of what rule set to answer under, it might be a good idea if the original poster asks a question, to specify in the subject line of the thread "Fed:" or "NCAA:" or "Football Canada:", etc. In rec.sport.officiating it got confusing when someone posted a question that might be about baseball, softball, cricket, or even other sports using some of the same terms (such as DQ of a player), until that convention was (mostly) adopted. Here we have division into different sports, but it can usually be sliced much finer, especially in football. And if you're interested in rulings of other bodies, then please don't specify one in the subject line and don't get bugged if someone gratuitously supplied more info than you need.

Robert