Final answer:
Civil Law (option A) governed the rights of Roman citizens to a trial and self-defense in court. This branch of law handled disputes between individuals, as opposed to criminal law, which involved offenses against the state.
Step-by-step explanation:
The right of citizens of Rome to a trial and defense in a court of law would be an example of Civil Law. Civil law governs disputes between individuals and includes a wide range of issues such as property disputes, contracts, and personal injury cases. In contrast, criminal law deals with offenses against the state or social order, such as violent crimes. It's important to distinguish these two as they have different standards of evidence and different purposes.
Civil cases generally revolve around restitution and compensation, while criminal cases are focused on punishment and societal protection. As Romans established various legal systems, they also introduced principles that are foundational to modern justice, such as the presumption of innocence and using precedent in legal decisions, and enabled citizens to defend themselves in legal matters.