On monday cindy says to ruth, " i will sell you my car for $10,000. you have until friday to decide." as of wednesday, ruth has paid nothing to cindy and has not indicated if she is interested in buying the car. at this point, which is true? a. cindy can revoke the offer on wednesday. b. ruth must reject cindy's offer by friday, or else she has bought the car. c. cindy cannot revoke the offer on wednesday. d. ruth could send $250 to cindy on friday which would automatically make the offer irrevocable for one month.