DB Offered to Sell a Cap for $10

Multiple Choice

DB offered to sell a cap for $10. Dan asked if she would give him 2 hours to think about it. She said, "Sure." Dan checked eBay, learned the hat was worth $100, but before he could call to accept the offer, she revoked it.​

A) There is a contract for the sale of the hat if the 2-hour period had not expired, because she promised to keep the offer open.
B) There is a contract for the sale of the hat, but only if the offer was in writing.
C) There is a contract because of the option.
D) There is no contract because DB revoked the offer prior to acceptance and there was no consideration for her promise to keep it open.