Ed mails an offer to Jim which is received on May 1. On May 2, Ed mails a letter revoking this offer which is received by Jim on May 8. On May 3, Jim mails a letter rejecting the offer and this is received by Ed on May 9. Finally, on May 4, Jim sends a letter of acceptance which is received by Jim on May 7. a. There is no contract because the rejection was mailed by Jim first. b. There is a contract effective May 4. c. There is a contract effective May 7. d. There is no contract because the revocation was sent by Ed first.