Concept:The 1950 All-Nigerian Constitutional Conference was notable for broadening African participation in Nigeria's constitutional discussions.
Explanation:Before 1950, Nigerian unofficial members had limited involvement in constitutional talks.
The All-Nigerian Constitutional Conference, however, included the full participation of all unofficial members of the legislative council.
This marked a major shift from previous conferences, where such representatives were largely excluded or sidelined.
The conference did not focus on organizing the federation purely on ethnic grounds, nor did it establish a quasi-federal structure at that point.
Official members of the legislative council were not the main participants; rather, the unofficial Nigerian members took centre stage.
Answer:D. all unofficial members of the legislative council participated.