Pick your ruling

[bisonlj]

ART. 1 . . . The offense is the team which is in possession of the ball. The opponent is the defense.
ART. 2 . . . A is the team which puts the ball in play. The opponent is B.
ART. 3 . . . K is the team which legally kicks the ball during the down. The
opponent is R.
ART. 4 . . . Team designations (A and B, K and R) are retained until the ball is
next marked ready for play.

You answered your own question with this rule posting.

Article 1 states the offense is the team in possession and article 4 doesn't state the team that snaps the ball retains this designation throughout the down. This use of wording is intentional. Whoever has the ball at that point in time is the offense. They may be team A, B, K, or R depending on their status at the start of the play.