Pam Poodle was opening a dog salon and needed someone to paint the salon. She wrote Bill Brush, a commercial painter, an e-mail stating "I'm opening up a dog salon next week and need someone to paint. If you come by and paint the shop, I'll pay you $2,500. Let me know, or just come by next week and start painting." Pam was out of town buying 9 supplies the next week, but Bill went to the salon and began painting. One week later, Pam saw Bill at the salon and told him she no longer needed him to paint the salon. Pam ordered Bill off her premises and has refused to pay him. Which of the following statements is most correct?
(A) Pam could revoke her offer at any time before the job was completed.
(B) A contract between Pam and Bill was formed when Bill began painting.
(C) Bill could walk away before finishing, but Pam could not terminate him without incurring contractual liability.
(D) Bill is entitled to the fair market value of the painting services he provided before Pam demanded he leave.