Which one of the following is NOT required for revocation of an offer to be effective?

In contract law, for an offer to be effectively revoked, certain conditions must be met, but it is not necessary for the revocation to be in writing. An offer can be revoked verbally or through conduct, as long as the offeree is made aware of the revocation before they accept the offer.

The other conditions are essential for effective revocation. Firstly, the revocation must occur before the offeree accepts the offer, otherwise, an acceptance completes the contract, and the offer can no longer be revoked. Secondly, the revocation must be communicated to the offeree, ensuring that they are aware that the offer has been withdrawn. Finally, it must be the offeror or an authorized agent who provides this revocation, as only the original party who made the offer has the authority to revoke it.

Since a written form is not a legal requirement for revocation, this understanding underscores why an offer does not need to be revoked in writing to be effective.