Is John's interest in a car advertised for $15,000 considered a valid offer?

In this scenario, John's interest in the car priced at $15,000 does not constitute a valid offer because he has not taken any action to accept the offer being made by the seller. An offer in contract law requires a clear proposal made by one party and acceptance by another. Simply expressing interest does not legally bind either party to a contract. Thus, John's action remains as a manifestation of interest rather than an acceptance, and without that acceptance, there is no agreement.

The other choices don't apply in this situation. A valid contract requires an acceptance of an offer, while terms like "lacks specificity" or "preliminary inquiry" do not accurately describe John's situation usually characterized by his lack of acceptance. Therefore, focusing on the requirement of acceptance clarifies why his interest alone doesn't fulfill the criteria of a valid offer or agreement.