Final table chip leaders head to head - Call or Fold?

[rookieplus]

6 handed HE, down to final 6, $4K+ for first, $650 for 6th.

Top two chip stacks ~200K are involved in this hand (BB and CO), 3rd place is under 120K.

UTG and UTG+1 fold, CO holding A [img]/images/graemlins/diamond.gif[/img]7 [img]/images/graemlins/spade.gif[/img] calls (6K), button and SB (3K) fold, BB (6K) checks option. Pot 15K plus antes.

Flop T, 7, 3 rainbow, BB checks, CO bets 6K, BB calls. Pot 27K+.

Turn 3, BB checks, CO bets 15K, BB pushes all in.

Both CO and BB have been playing TA.

CO - What do you do here?