River card comes and the donk donks into me

[Daddy Warbucks]

Villain is 43/23/5 over 200 hands. I've never played with him before and don't have much of a read. The table has been playing pretty passive, and i've been playing pretty wide open and taking down a lot of pots uncontested. I'm prepared to dump the hand at any stage if raised, but when he donks, i wasn't sure what course of action is bet. One word answers are fine, raise, call or fold?

Party Poker, $0.50/$1 NL Hold'em Cash Game, 5 Players
LeggoPoker Hand History Converter

SB: $78.75
BB: $53.38
UTG: $121.26
CO: $30.61
Hero (BTN): $170.83

Pre-Flop: 9[img]/images/graemlins/spade.gif[/img] 6[img]/images/graemlins/spade.gif[/img] dealt to Hero (BTN)
2 folds, <font color="red">Hero raises to $4</font>, SB calls $3.50, BB folds

Flop: ($9) J[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/spade.gif[/img] J[img]/images/graemlins/spade.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $6</font>, SB calls $6

Turn: ($21) 4[img]/images/graemlins/spade.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $13</font>, SB calls $13

River: ($47) T[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">SB bets $22</font>, Hero ?