Which of the following is necessary for a contract to be valid and enforceable?

A contract must have valuable consideration to be valid and enforceable. Valuable consideration refers to something of value exchanged between the parties involved in the contract. This can be money, services, or goods, and it establishes the mutual agreement and intent of the parties to enter into the contract. Without this consideration, a contract may be viewed as a gift rather than a legally binding agreement.

While handshake agreements can indicate mutual consent, they do not provide the necessary legal framework to make the contract enforceable in all situations. The involvement of a real estate agent, although common in property transactions, is not a strict requirement for the validity of a contract. Similarly, a notary public's signature is not essential for most contracts; while it can add a level of verification, many contracts remain valid without notarization. Therefore, the presence of valuable consideration is critical in ensuring that a contract is both valid and enforceable under the law.