In an executory bilateral contract, most courts hold that:

Multiple Choice

if a contract has been fully performed by one side, the promise of the other party is enforceable even if it cannot be performed within a year.

even if a contract has been fully performed by one side, the other party may choose to not enforce its side of the contract.

even if a contract has been fully performed by one side, the other party has no legal obligation to enforce its side unless it is in writing.

if a contract has been partially performed by one side, the promise of the other party is enforceable if it is communicated orally.