Which contract is created when only one party makes a promise to perform?

• A. Unilateral contract
• B. Voidable contract
• C. Executed contract
• D. Void contract

Answer: (A)

When only one party promises to perform, the contract is a unilateral contract. The offeror’s promise sets up the terms, but acceptance comes through the other party’s actual performance of the requested act. There’s no binding agreement until that performance occurs, and the promisor is obligated to fulfill the promise once performance is completed. A classic example is a reward offer: “I’ll pay $100 to anyone who returns my lost dog.” There’s no promise to act on the part of the finder; the contract comes into existence only when the dog is returned.

This differs from a bilateral contract, where both sides promise to perform; an executed contract is one where performance has already occurred by both parties; and a void contract is unenforceable from the start.