Multiple choice Valid contract in case of this, collateral agreements are void not enforceable in a court of law an agreement enforceable by law at the option of one or more of the parties thereon but not at the option of the other or others enforceable at the option of both the parties Reveal answer Fill a bubble to check yourself D Correct answer Explanation A valid contract is one that is enforceable by law in a court of law. The definition requires enforceability at the option of both parties (not just one). Option C describes voidable agreements, while options A and B describe invalid contracts.