Which of the following countries has a federal form of government with two-tier dual citizenship…

The United States of America is the classic model of a federal system with two-tier dual citizenship: under the Fourteenth Amendment to the US Constitution, every citizen is simultaneously a citizen of the United States (federal) and of the individual State in which they reside. By contrast, India is a federation with single citizenship across the entire country; the United Kingdom has a unitary system with single citizenship; and Switzerland operates a three-tier citizenship system (municipal/communal, cantonal, and federal under Article 37 of the Swiss Constitution).