foul at end of first half

[jTheUmp]

Under FED rules, a foul by Team B on a scoring play can be enforced at the succeeding spot... which, in this case, is the opening kickoff of the second half.

So, Team A has two (well, three, but they'd never take the 3rd one) choices:
1) accept the penalty, enforce from the previous spot, and have an untimed down.
2) accept the result of the play, enforce the penalty on the succeeding kickoff at the start of the second half.
3) decline the penalty (there is no possible reason for Team A to EVER do this).