[VanVeen]

Bet $200-$275 and fold to a raise. More worse hands will call (many will call with any ace a significant % of the time) than bet (most won't continue bluffing missed flush draws or with trash when you've called a minraise on the flop) and you are not folding. Of course, the worse hands that will bet will probably bet more than worse hands will call, but I really doubt they do it often enough to compensate for the value you lose by checking.

I try to play in such a way that rivers like this are easy bets that will always get a call from most players. Worrying about river bluff raises is a waste of time. Most don't attempt them because they're either passive or because they're smart enough to notice that almost everyone calls anyway.