Decentralisation of power is a feature of a

Step 1: Analyse the question The question asks which system of government has decentralisation of power as a feature. Decentralisation means power is shared or spread between the central government and smaller units (states, regions, or provinces), rather than being concentrated in one place.

Step 2: Review the concepts

• Unitary state: Power is concentrated in the central government. Any regional or local units exist only because the centre allows them (e.g. the UK, France). This is centralisation.
• Confederal state: Independent states come together loosely, and the central body is weak. Power largely stays with the member states. It is a loose union, usually called "devolution to the units" rather than decentralisation by a constitution.
• Parliamentary state: This describes the relationship between the executive and the legislature (the executive is drawn from and answerable to parliament). It says nothing about how power is distributed between levels of government.
• Federal state: Power is constitutionally divided between the central government and the component units, and each level is coordinate and independent in its own sphere (e.g. Nigeria, USA). This is the classic example of decentralisation of power.

Step 3: Apply to the question Federalism is the system where the constitution itself splits powers between the federal government and the states (in Nigeria, the Exclusive, Concurrent and Residual lists). So decentralisation is a defining feature of a federal state.

Step 4: Answer The correct option is D. Federal state.

Tip: Remember the keywords:

• Unitary = United power at the centre (centralised)
• Federal = Formally shared power (decentralised)
• Confederal = Centre is weak

In exams, when you see "decentralisation" or "division of powers," think federalism.