Which of the following best describes a valid contract?

A valid contract is fundamentally characterized by mutual consent among all parties involved. This means that all parties agree to the terms and conditions of the contract willingly and without coercion. Such consent indicates that there is a meeting of the minds, which is essential for the formation of a legally enforceable agreement.

While a written document or oral communication can play a role in forming a contract, the key element is the mutual agreement to the contract's terms. This agreement can be presented in various forms, be it written, verbal, or implied by the parties' conduct, as long as the essential elements of a contract—such as offer, acceptance, and consideration—are met.

The fact that mutual consent is vital highlights why formalities like writing or signing are not the primary determinant of validity. Contracts can be valid without being written or signed, provided that all parties understand and agree to the terms involved. This aspect underscores the importance of clarity and agreement over the medium through which that agreement is expressed.