Explanation:

- Option 1: A valid contract

- A valid contract requires an offer, acceptance, and consideration. Simply stating a minimum price does not meet these requirements as it lacks acceptance and intent to create legal obligations.

- Option 2: An implied contract

- An implied contract forms through the actions or conduct of the parties, rather than through verbal or written agreements. A statement of minimum price alone does not imply a contract.

- Option 3: An express contract

- An express contract is formed explicitly through written or spoken words of offer and acceptance. A simple price statement does not constitute an express contract by itself.

- Option 4: No contract

- A statement of the lowest price is more an invitation to negotiate or make an offer, and not a binding agreement.