River nutflush on paired board facing shove

Posted 9 years, 5 months ago

Blinds: $0.10/$0.25 (6 Players) BN: $25.35 (Hero)
SB: $20.47
BB: $26.29
UTG: $52.51
MP: $30.14
CO: $20.71

Preflop ($0.35) Hero is BN with K 6

3 folds, Hero raises to $0.50, SB calls $0.40, BB calls $0.25

Flop ($1.50) A 8 9

SB checks, BB checks, Hero bets $1.10, SB folds, BB calls $1.10

Turn ($3.70) A 8 9 K

BB checks, Hero bets $2.75, BB raises to $7.75, Hero calls $5.00

River ($19.20) A 8 9 K 9

BB bets $16.94 and is all in

Vs unknown.
Is river a call?
What hands can he play like this?