In hold em a player goes all in for less than 50% of the last raise. can the first raiser then reraise?

Question

the blinds are 100/200. Player A raises from 200 to 550. Player B calls, and player C goes all in for 600. Does this constitute a raise, and can player A now reraise to drive out player B? I've seen it two different ways online, and heard it differently from different people.

Answer 1

He can't re-raise if this is limit hold'em but all can call the 50 more that the all-in put in. If this is no-limit he can re-raise.

Answer 2

If Player C goes allin for 600, player A can reraise to whatever
amount he likes beyond 600 including the entire stack. If Player
B calls for 550, then Player C is reraising from 550 to 600. The
other players have to match to see a flop, assuming they have C
covered. Since Player C has reraised the pot to 600 allin, Player A has the option of calling, folding, raising or reraising. Player B
has those options as well, but must wait in turn to see what happens. In other words, Player B can't act until Player A decides
what to do. You have to tell us which version of Holdem are we
talking about? Fixed-Limit, Pot-Limit, or No-Limit Texas Holdem?

Answer 3

Player A and B can only call at this point. Exception: if a Player D raises to 900 (another 350 above the 550) or more the betting can continue.

Answer 4

this does not constitute a raise..it is less than half the original raise... the a bettor cannot raise himself..