Correct Option (A):
The independence of the judiciary is a fundamental characteristic of a federal system. An independent judiciary serves as the interpreter and guardian of the Constitution, ensuring the supremacy of the Constitution and resolving disputes between the Union and the States. This mechanism is essential to maintain the constitutional division of powers and prevent either level of government from encroaching upon the other's jurisdiction, thereby upholding the federal structure.
Incorrect Options:
The presence of elected representatives from constituent units in the Union Legislature is not an exclusive feature of federalism. Such representation can also be found in unitary systems, where local or regional bodies may send representatives to the national legislature. Therefore, this feature alone does not definitively indicate a federal character.
The inclusion of elected representatives from regional parties in the Union cabinet primarily reflects the dynamics of political representation, coalition politics, or the electoral outcomes within a parliamentary system. It is a political arrangement rather than a defining structural feature of a federal polity.
The enforceability of Fundamental Rights by courts of law is a crucial aspect of a democratic system, safeguarding individual liberties against state action. While essential for a constitutional democracy, this feature pertains to the protection of individual rights and does not directly signify the federal character of a state, which primarily concerns the division of powers between different levels of government.