MClays99 is correct, but...
On the Last Play...
IW on the Back Judge after the COP.
UNS on B25 after the IW.
Since their is 0:03 remaining, Per NFHS 4-2-3c, B (now A), will undoubtedly take the result of the play, which is a Touchback. Place the ball on the B (now A) 20.
A (now B) will undoubtedly accept the UNS which moves the ball to the B (now A) 10.
B (now A) takes a knee at the B (now A) 9 yard line - Game over.
Back Judge buys beer for distinguishing himself as the newest member of the exclusive club of officials who have blown an IW in a state championship game!