Concept:Separation of powers gives each arm of government distinct functions and limits.
Explanation:The judiciary interprets the law and acts as the guardian of the constitution.
Through the power of judicial review, the judiciary can examine laws made by the legislature.
If a law violates the constitution, the judiciary has the authority to declare it unconstitutional and invalid.
This power helps maintain checks and balances among the arms of government.
The legislature only makes laws, while the executive enforces them, but neither has the final power to nullify an existing law.
Therefore, the judiciary is the correct arm of government that can declare laws unconstitutional.
Answer:A. Judiciary