Which one of the following is not a feature of a federal system of Gov

Which one of the following is not a feature of a federal system of Government ?

Division of powers between the Central and State Governments
A written Constitution
Single citizenship
Bicameral legislature
This question was previously asked in
UPSC Combined Section Officer – 2021-22
The correct answer is C) Single citizenship.
A federal system is characterised by features such as the division of powers between different levels of government, a written constitution to define this division, the supremacy of the constitution, independent judiciary, and often a bicameral legislature (where one house represents the units of the federation). Single citizenship is a characteristic of the Indian federal system (which has unitary biases) but is not a defining or universal feature of all federal systems. Many classical federal states like the USA have dual citizenship (citizenship of the federation and citizenship of the state).
India’s Constitution, while federal in structure with division of powers, written constitution, etc., incorporates several unitary features, including single citizenship, a strong centre, single integrated judiciary, and emergency provisions.