Donked into by a donkey. what's my play?

[Mossberg]

yea yea this is 2/4 but these games play soft and I figured this hand was too basic to post in MSNL.

Anyways, my stats on villain aren't up yet, but I have him buddylisted and I have a note suggesting he is very loose preflop, and passive postflop as well. I think this donk is often a plea from a draw to see a cheap river, but I definitely can't rule out big hands, though they do seem unlikely to me. What's your plan here?

Blinds: $2/$4
4 players
Converter

Stack sizes:
UTG: $413.70
Hero: $400.00
SB: $398.00
BB: $437.10

Pre-flop: (4 players) Hero is Button with T[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/spade.gif[/img]
UTG folds, <font color="#cc0000">Hero raises to $16</font>, SB calls, BB calls.

Flop: 9[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/diamond.gif[/img] A[img]/images/graemlins/diamond.gif[/img] ($48, 3 players)
SB checks, BB checks, <font color="#cc0000">Hero bets $35</font>, SB calls, BB folds.

Turn: A[img]/images/graemlins/spade.gif[/img] ($118, 2 players)
<font color="#cc0000">SB bets $40</font>, Hero ____________?