In Texas Hold'em, who is awarded second and third place in this scenario?
Here, the important factor is that Player B and Player C both lost to, and were "busted" by Player A's hand. Not that Player C's hand beats Player B's.

If two players "bust out" on the same hand, then the prizes are awarded in DESCENDING chip order as of BEFORE the mutual bust. That is Player B comes in ahead of Player C.

If Player C had sat out with 50 chips, and only Player B was busted, Player C would continue. (And probably win second place unless he were able to stage a complete reversal.)