Concept:Decree 34 of 1966 replaced the federal system of government with a unitary system, causing widespread opposition.
Explanation:The federal government introduced Decree 34 on May 24, 1966, under General Aguiyi-Ironsi.
The decree was designed to unify Nigeria by abolishing the regions and creating a centralized administration.
This change was perceived as an attempt to remove the federal structure that protected the interests of various ethnic groups.
Many Nigerians, especially in the North, saw the decree as a threat to their autonomy and political representation.
Therefore, its main source of rejection was the perception that it abolished the federal system.
Answer:C. perceived to abolish the federal system.