bottom end of a str8 in an unraised pot

[demon102]

PokerStars No-Limit Hold'em, $0.25 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($28.30)
SB ($13.90)
BB ($25)
UTG ($23.80)
UTG+1 ($25.95)
MP1 ($2.45)
MP2 ($23.15)
MP3 ($8.65)
CO ($5)

Preflop: Hero is Button with 4[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, MP1 calls $0.25, <font color="#666666">1 fold</font>, MP3 calls $0.25, <font color="#666666">1 fold</font>, Hero calls $0.25, <font color="#666666">1 fold</font>, BB checks.

Flop: ($1.10) 8[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">BB bets $0.75</font>, MP1 folds, MP3 folds, <font color="#CC3333">Hero raises to $1.75</font>, BB calls $1.

Turn: ($4.60) 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $2</font>, BB calls $2.

River: ($8.60) K[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $2.9</font>, <font color="#CC3333">BB raises to $5.8</font>, Hero ?

No reads here. I am wondering what u guys would do here. Call, shove all in? Im only scared of one hand really onless someone and I cant narrow his range at all. What would u do?