Final answer:
Sunday contracts, known as blue laws, vary by state and are the result of legislative statutes. Their enforcement is not uniform across the country, and they have been subject to judicial interpretation, which can influence their application.
Step-by-step explanation:
The statement C) Their laws are a result of statutes is true of Sunday contracts. These contracts, often referred to as blue laws, restrict certain activities on Sundays and are established through legislative statutes. These laws are not universal across states, as their implementation and the judicial interpretation of these laws can vary from one state to another. The courts have sometimes upheld such laws when they appear to establish certain religious practices, such as limiting working hours or closing businesses on Sundays. However, it is not mandatory to prosecute all violators of such contracts, and judicial interpretation certainly has had an impact on their formulation.
Furthermore, both state and federal courts can hear matters involving these laws, as they may pertain to both civil and criminal law. It's important to recognize that while the U.S. Constitution sets a binding framework, state laws and interpretations by state courts can lead to a diversity of legal applications across the nation.