B.one party can restrict the performance of another party QUIZ - WK 4 - Defenses to Enforceability.This book provides an understanding of contract law and gives a clear and systematic approach to analysing and answering problem and exam questions. The contract allows Wayne to have a 30 day inspection period to include a physical inspection of the real estate. When a court says that an agreement is illegal, it most likely means that the agreement: violates public policy. This quiz and worksheet gauge your understanding of the different types of contract law. You will be assessed on different types of contracts.