Unitary system of government is adopted by some states because

1. Analyze the question The question asks why some states adopt a unitary system of government, where power is concentrated in one central government.

2. Explain the concept In a unitary system, the central government holds supreme authority. Regional or local units exist only by the central government's permission. This system works best in states that are:

• Small in size
• Socially and culturally homogeneous (people share a common language, culture, religion, or ethnicity)
• Free of strong regional or ethnic divisions that would demand self-government

Federalism, on the other hand, is usually adopted by large, diverse, multi-ethnic states that need to protect the autonomy of different groups, as in Nigeria.

3. Evaluate the options

• A. Homogeneity. Correct. When people share a common identity, there is little need to divide power among regions, so one central government can rule effectively. Examples include Ghana, Japan, and France.
• B. It guarantees democracy. Incorrect. A unitary system can be democratic or authoritarian. Concentrated power does not guarantee democracy, and federalism is often considered better at spreading power.
• C. It builds the capacity of citizens in good time. Incorrect. This is not a recognised reason for adopting the system. Building citizens' capacity is not tied to the structure of government.
• D. Mineral resources. Incorrect. Resource endowment does not determine the choice of system. Resource control actually often causes disputes in federations.

4. Answer The correct option is A.

5. Exam tip Link the systems to the nature of the society:

• Unitary = homogeneous, small society
• Federal = heterogeneous, large, diverse society

If a question asks why a system was adopted, think of the type of society first.