Unitary State: A unitary state is a form of government in which power is concentrated in a central authority, with regional and local governments deriving their powers from the central government. In a unitary state, the central government has the authority to create and abolish regional and local governments, and there is no constitutional division of powers between the central and regional governments.

Among the options given, France is a unitary state.

Explanation:

1. France: France is a unitary state where power is concentrated in the central government in Paris. The French government exercises authority over the entire territory of France, including its regions and departments. Regional and local governments in France derive their powers from the central government and do not have independent powers to create or abolish regional or local governments.

2. United States: The United States is not a unitary state. It is a federal state where power is divided between the central government and the individual states. The U.S. Constitution establishes a division of powers between the federal government and the state governments, with certain powers reserved to the states.

3. Venezuela: Venezuela is also not a unitary state. It is a federal republic where power is divided between the central government and the states. The Venezuelan Constitution establishes a division of powers between the federal government and the state governments, with certain powers reserved to the states.

4. Nigeria: Nigeria is not a unitary state either. It is a federal republic where power is divided between the central government and the states. The Nigerian Constitution establishes a division of powers between the federal government and the state governments, with certain powers reserved to the states.

In conclusion, France is the only option among the given choices that is a unitary state. The United States, Venezuela, and Nigeria are federal states where power is divided between the central government and the regional or state governments.