Concept:The creation of Nigeria’s first 12 states was a major administrative reform carried out by a military government.
Explanation:Before 1967, Nigeria was divided into four regions: Northern, Western, Eastern, and Mid-Western.
General Yakubu Gowon announced a decree on 27 May 1967 that abolished these regions.
The decree split the country into 12 new states to reduce regional dominance and promote national unity.
This change took effect on 27 May 1967, shortly before the Nigerian Civil War began.
Therefore, the formation of the first 12 states happened in 1967, not in 1966, 1976, or 1987.
Answer:C. 1967