Multi-Treasure Logic

Logic

You are in a room with three chests. You know at least one has treasure, and if a chest has no treasure, it contains deadly poison.

Each chest has a message on it, but all the messages are lying.

Left chest: "The middle chest has treasure."
Middle chest: "All these chests have treasure."
Right chest: "Only one of these chests has treasure."

Which chests have treasure?

Only A has treasure A and C have treasure Only B has treasure B and C have treasure Only C has treasure All of the chests have treasure A and B have treasure