A structure of government in which power is shared between the centre and the units is

1. Analyze the question The question asks for the system of government in which power is shared between the central (national) government and the units (states, regions, or provinces).

2. Explain the concept Governments are classified by how power is distributed:

• Federalism: Power is constitutionally divided between the central government and the component units. Each level has its own area of authority and neither can take away the other's powers at will. Nigeria, the USA, and India are examples.
• Confederal: The units are the stronger partners, and the centre is weak. It exists only by their consent and depends on them. Power is not really shared, because the units hold most of it.
• Unitary: All power is concentrated in the central government. Any local units exist only because the centre delegates authority to them, and it can withdraw that authority. Examples are the UK and France.
• Oligarchic: This describes rule by a small group. It is a type of rulership, not a way of distributing power between a centre and units.

3. Step-by-step solution

• The key phrase is "power is shared between the centre and the units."
• Unitary: power is not shared, since it is concentrated at the centre. Eliminated.
• Oligarchy: it concerns who rules (a few people), not a centre-unit structure. Eliminated.
• Confederal: the units are dominant and the centre is merely a coordinating body. It is not a constitutional sharing of power. Eliminated.
• Federalism: power is constitutionally shared and divided between the centre and the units. This matches the question.

4. Answer The correct option is D. federalism.

5. Exam tip Remember the key words for each system:

• Federal = Formally shared power
• Unitary = United in one centre
• Confederal = Centre is weak, units are strong

If you see "power is shared/divided between the centre and the units," think federalism straight away.