The correct option for the question "When Nigeria achieved independence in 1960, the head of state was the" is C. Governor-General. Detailed Explanation:

1. Understanding Nigeria's Political Structure at Independence:
2. When Nigeria gained independence from British colonial rule on October 1, 1960, it was still a member of the Commonwealth of Nations. This meant that while Nigeria was self-governing, it still recognized the British monarch as the head of state.
3. The position of the head of state in Nigeria at that time was held by the Governor-General, who represented the British monarch in Nigeria. The Governor-General was responsible for ceremonial duties and had certain constitutional powers.
4. Role of the Governor-General:
5. The Governor-General acted as the representative of the Queen of England (the monarch) in Nigeria. This role was significant because it symbolized the transition from colonial rule to self-governance while still maintaining a connection to the British monarchy.
6. The first Governor-General of independent Nigeria was Sir James Wilson Robertson, who served until the position was abolished in 1963 when Nigeria became a republic.
7. Transition to a Republic:
8. In 1963, Nigeria adopted a new constitution that established it as a republic, and the position of Governor-General was replaced by that of a President. This change marked a significant shift in Nigeria's political landscape, as the President became the head of state and government.

Why the Other Options are Incorrect:

• A. President:
• This option is incorrect because Nigeria did not have a President at the time of independence in 1960. The presidential system was established later in 1963 when Nigeria became a republic.
• B. Prime Minister:
• While Nigeria did have a Prime Minister after independence, the Prime Minister was not the head of state. The Prime Minister was the head of government, responsible for running the country and making policy decisions. At independence, the head of state was still the Governor-General.
• D. Queen of England:
• This option is misleading. While the Queen was the monarch and the ultimate head of state, she did not directly govern Nigeria. Instead, her representative, the Governor-General, performed the ceremonial duties and functions associated with the head of state. Therefore, the Queen herself was not the head of state in the practical sense within Nigeria.

Summary of Key Points:

• Nigeria achieved independence on October 1, 1960, with the Governor-General as the head of state.
• The Governor-General represented the British monarch and held ceremonial powers.
• The transition to a republic in 1963 replaced the Governor-General with a President as the head of state.
• The Prime Minister was the head of government, not the head of state.

This understanding of Nigeria's political structure at the time of independence is crucial for grasping the historical context of governance in Nigeria and the evolution of its political system.