Hand converted with online PokerStrategy.com hand converter:
$2/$4 Fixed-Limit Hold'em (6 handed)
Preflop: Hero is MP3 with Q:h, J:h.
MP2 folds, Hero raises, 3 folds, BB calls.
Flop: (4.5 SB) A:s, 5:d, 3:d (2 players)
BB bets, Hero ??
Let's assume BB is unknown. Fold?