Which legal doctrine requires certain contracts to be in writing to be enforceable?

• A. Promissory notes
• B. Oral service contracts
• C. Statute of Frauds
• D. Parol evidence rule

Answer: (C)

The Statute of Frauds is the rule that certain contracts must be in writing to be enforceable. It targets agreements that are easier to dispute or misremember, so a written form provides clear evidence of the deal. This doctrine specifically covers categories like real estate transactions, contracts that cannot be completed within one year, promises to pay the debt of another, and contracts for the sale of goods above a certain amount. Because the question focuses on which rule requires a writing for enforceability, the Statute of Frauds directly answers it. Promissory notes are themselves written promises to pay, so they’re not a doctrine about requiring writing. Oral service contracts can be enforceable unless they fall into one of the Statute of Frauds categories. The parol evidence rule deals with whether written terms can be supplemented or contradicted by outside communications, not with whether writing is required for enforceability.