Anton made a bid at an auction by calling out the amount of $250. The auctioneer noted Anton's bid. There were no higher bids, and Anton called out that he was withdrawing the bid, before the auctioneer said it was accepted. The auctioneer said that it was too late to withdraw the bid. a. Anton's bid is an ordinary offer that can be revoked. b. Anton's bid is firm and can not be withdrawn. c. By noting that Anton's bid was received, the bid became an option. d. By noting that Anton's bid was received, that was an acceptance of Anton's offer e. None of these