In what type of law is Fred being prosecuted if Barney sues him after a car wreck?

In the scenario where Barney sues Fred after a car wreck, the type of law being applied is primarily civil law. Civil law deals with disputes between individuals or organizations, typically involving matters such as contracts, property, and torts, which includes personal injury claims like those arising from car accidents. In this context, Barney seeks compensation for damages resulting from Fred's alleged negligence, which falls under tort law.

Additionally, the nature of the legal relationship between the parties can also be considered private law, as it pertains to the rights and obligations of individuals in private legal matters. Private law encompasses areas like family law, contract law, and tort law, focusing on the interactions among private entities.

Thus, the correct understanding of the law involved in this situation captures both civil law and private law elements, making the combination of these categories the appropriate answer.