Concept:At independence in 1960, Nigeria was a constitutional monarchy, so the British monarch was the head of state.
Explanation:Nigeria gained independence from the United Kingdom on 1 October 1960.
Under the 1960 constitution, Nigeria remained a Commonwealth realm with a parliamentary system.
Queen Elizabeth II, the Queen of England, became the head of state.
She was represented in Nigeria by a Governor-General, who acted on her behalf.
The Prime Minister, Abubakar Tafawa Balewa, was the head of government, not the head of state.
Option B, President, is wrong because a president was only introduced after Nigeria became a republic in 1963.
Option D, Governor-General, is wrong because the Governor-General was the Queen's representative, not the head of state.
Therefore, the correct answer is the Queen of England.
Answer:A. Queen of England