Correct Option
Constitutional government signifies a system where the powers of the government are explicitly defined and restricted by a constitution. This limitation ensures that governmental authority is exercised within prescribed boundaries, preventing arbitrary rule. Key features include the rule of law, protection of individual liberties, and accountability of the government to the constitutional framework. In India, this is exemplified through provisions like Fundamental Rights (Part III), separation of powers, and an independent judiciary, which collectively enforce these limitations.
Incorrect Options
Option (a): A representative government of a nation with federal structure. This describes a specific form of government (representative democracy) and its structural arrangement (federalism). While a constitutional government can be federal and representative, these characteristics are not its defining essence. A constitutional government fundamentally refers to the limitation of governmental power by a constitution, irrespective of its federal or unitary nature, or whether it is representative.
Option (b) and (c): A government whose Head enjoys nominal powers. This characteristic primarily defines a parliamentary system of government, where the Head of State (e.g., President or Monarch) holds ceremonial powers, and real executive power rests with the Head of Government (e.g., Prime Minister). While many constitutional governments adopt a parliamentary system, the concept of a constitutional government is broader, focusing on the limitation of power by a constitution, which can also exist in presidential systems where the Head of Government holds real power. Therefore, nominal powers of the Head are not a universal or defining feature of constitutional government.