Which type of contract is formed through the actions of the parties involved?

An implied contract is formed through the actions and conduct of the parties involved, rather than through explicit verbal or written agreement. This type of contract arises when the behavior of the parties indicates that they intend to enter into a contract, even if no formal agreement has been established or documented. For example, if a person visits a doctor for treatment, the actions of seeking medical help imply that there is a contract for services in which the doctor agrees to provide care, and the patient agrees to pay for those services.

In contrast, express contracts involve clear, written, or spoken terms explicitly agreeing to the contract's requirements. Written contracts are a subset of express contracts where the terms are documented in a formal written format. Unilateral contracts involve one party making a promise in exchange for an act by another party, which also typically requires some affirmative action rather than just implied behavior. The defining characteristic of implied contracts is that they are based on inferred intentions rather than overt statements, making them distinct among the options provided.