A federal constitution is characterized by a division or distribution of powers between a central government and regional governments (like states or provinces). This division is typically enshrined in the constitution, and each level of government operates within its defined sphere of jurisdiction. Options A, B, and C, while important aspects of governance in many countries, are not the fundamental defining features of a federal system. Election Commission and Supremacy of Judiciary are crucial for a democratic and constitutional government but can exist in unitary systems as well. Parliamentary Supremacy is characteristic of a unitary system (like the UK), where the Parliament is the supreme legal authority, whereas in a federal system, the Constitution is supreme.