Which of the following must be included in a valid contract?

A valid contract must include an offer and acceptance because this is the foundational principle that establishes mutual agreements. When one party makes an offer, they are proposing the specific terms of the agreement. The other party must then clearly accept those terms for the contract to be binding. This mutual consent is essential; without it, there is no contract. The offer outlines what is being agreed upon, and the acceptance demonstrates that the other party is in agreement with those terms.

While the names of the parties involved, a specific date for completion, and witness signatures can be important elements of a contract, they are not universally required for the contract to be valid. Having identifiable parties and specified deadlines can help avoid ambiguities and ensure enforceability, but the core aspect that a contract requires is the clear offer and acceptance to demonstrate a meeting of the minds. Witness signatures can add an additional layer of authenticity but are not necessary for the existence of a contract.