William offers to sell Brenda a lawn mower for $100. While Brenda is considering the offer, her friend Jake replies that he will accept the offer and purchase the lawnmower. There is:_________.
a. no contract formed because Jake is unable to accept an offer from William without Brenda's consent
b. a contract formed because Jake accepted William's offer
c. a contract formed because William made a valid offer
d. no contract formed because William made the offer only to Brenda