Which type of public law involves the interpretation and application of constitutions?

The correct answer focuses on constitutional law, which is specifically concerned with the interpretation and application of constitutions. This area of public law addresses the framework of government and the rights of individuals within a state, as articulated in a country's constitution.

Constitutional law encompasses various principles and legal precedents that help to interpret the meaning of constitutional provisions, ensuring that laws and government actions conform to constitutional standards. It deals with important issues such as the division of powers, checks and balances, and the protection of civil rights and liberties.

Other areas of public law, while significant, do not primarily concentrate on constitutional interpretation. For instance, administrative law governs the activities of administrative agencies and focuses on regulations and procedures rather than the foundational legal principles set out in constitutions. Criminal law, on the other hand, deals with offenses against the state and the associated penalties, and international law refers to the set of rules that govern the relations between states and other international actors. Each of these fields has its own distinct focus, making constitutional law the appropriate choice for questions relating specifically to the interpretation and application of constitutional text and principles.