NL50: River gives set, fold?

[Danielmk]

Practically there is only one hand besides another the set that beats you. (he would have to be a donkey if he had a set and played it like this). So just a 46 beats you. He can either have a T2 or a 52, 32. Probably he will have more often the straight than these combinations and since the pot odds are not that great i will fold it. And the fact that he may be bluffing is out of the question. A little read here would make the difference between folding and calling.