50NL - Overpair facing flop c/r

[LadyMuck]

Want to get some feedback on this situation. Just recently there seems to have been an increase in c/r & r/r on the flop, some of it genuine and obv. some of it is done with air. In this situation villain (17/15/3) calls in the BB, then c/r the flop bet. He would have r/r pf w/ AA or KK, and prob not called w/ 65 or A5, leaving a set as the most likely hand he could have that beats me. Do you fold, call, or 4 bet the flop here?

BB ($49.25)
Hero ($50)
MP ($49.25)
CO ($53.15)
Button ($62.05)
SB ($50.85)

Preflop: Hero is UTG with Qd, Qc.
Hero raises to $1.75, 4 folds, BB calls $1.25.

Flop: ($3.75) 4s, 3c, 2s (2 players)
BB checks, Hero bets $2.4, BB raises to $7.45, Hero ???