Which one of the following in Indian polity is an essential feature that indicates that it is federal in character?

The correct answer is: The independence of judiciary is safeguarded.

Explanation:

A federal system of government is characterized by a division of powers between the central (national) government and the state (regional) governments. For a political system to be truly federal in character, several essential features must be present:

1. Dual Polity: Existence of two levels of government (Union and States).
2. Written Constitution: Clear distribution and specification of powers.
3. Rigid Constitution: The provisions regarding federal structure cannot be unilaterally altered by the central government.
4. Supremacy of the Constitution: The Constitution is the supreme law of the land.
5. Independent Judiciary: An independent and impartial judiciary is essential to resolve disputes between the Union and the States, or among the States themselves, and to prevent any arbitrary encroachment of constitutional division of powers.

Among the given options, the independence of the judiciary is a fundamental and essential feature that safeguards the federal structure of Indian polity by preserving the constitutional supremacy and division of powers.