On January 8, Quastrar, Inc. sent Hylavian Company a letter offering to sell $10,000 in restaurant supplies. On January 18, Hylavian mailed a letter to Quastrar accepting the offer. Quastrar received the acceptance letter on January 20. On January 17, Quastrar sent a letter revoking the offer. Hylavian received this letter on January 21. A contract between Quastrar and HylavianA. was formed on January 18.B. was formed on January 20.C. was not formed because the revocation was effective before the acceptance was received.D. was not formed because the revocation was effective before the acceptance was sent.

To determine whether the contract is formed betwen Quastrar and Hylavian, it is essential to determine whether the acceptance from Hylavian through mail on 18 January bid the two parties into a contract.

We apply Adams v. Lindsell (1818) B & Ald 681 which later formed a postal rule under common law system, stating that if an offer is accepted through mail, the timing of the acceptance will be at the time the mail is sent. While revocation of an offer is not effective after the offeree posted their acceptance through mail.

In this case, the Acceptance is sent on January 18, before the Revocation is received on 21st January. Thus, the Acceptance is effective and the contract is formed on the 18th January, at the time the acceptance is made.