2nd nuts, Big Pot

[Slinky]

The following happened in a 10-10-20 PLH game. According to “player A” the whole table was on tilt, except “A” himself. A had a stack of $10,000 , the player to his left had $12,000. They had everybody else covered.

A limped in UTG with Aces. Clearly, since the money was rather deep, and there where at times many raises and re-raises preflop, the best play was to raise here, but never mind that.

Three other players limp in, the two $10 blinds fold, the big blind checks.

Flop: A-K-8 bow.

A bets $100, B calls.

Turn: A-Qh-4-Kh

A bets $300, B raises $800 more, A calls.

River: A-Qh-4-Kh-8

A checks, B bets $2000 in to a $2520 pot. A has $8780 left. What should A do?