Which is NOT a way an offer can be terminated?

An offer can indeed be terminated through several mechanisms, but negotiation does not directly result in the termination of an offer. In most contexts, negotiation involves discussions between the parties about the terms of the offer, which may lead to a counter-offer or acceptance. However, it does not automatically nullify the original offer unless a mutually agreed-upon conclusion is reached that modifies or cancels the initial proposition.

Acceptance, withdrawal, and revocation, on the other hand, are all clear ways to terminate an offer. Acceptance finalizes the agreement, thereby concluding the offer successfully. Withdrawal allows the offeror to take back their proposal before it is accepted, and revocation occurs when the offeror rescinds the offer before it is acted upon. Thus, while negotiation is an important process in the realm of contracts, it does not function as a mechanism for terminating the offer itself.