The Postal Acceptance Rule states that an acceptance of an offer becomes effective at the moment it is dispatched, typically when it is put in the mailbox, regardless of whether the offeror has received it or not. This principle is rooted in the notion that once the acceptance is sent, the offeree has fulfilled their obligation to communicate their acceptance.
The idea behind this rule is that it prevents the offeree from being held liable for delays or mishaps in communication beyond their control, such as postal delays. Therefore, option C is correct because it accurately reflects this moment of effectiveness as defined by the Postal Acceptance Rule.
This principle is commonly applied in contract law to determine the point at which a binding agreement is formed, allowing both parties to rely on the clarity of the communicated acceptance.