Concept:Elective principle means allowing citizens to vote for their representatives in the legislative council.Explanation:The Clifford Constitution of 1922 first introduced the elective principle in Nigeria.It allowed for four elected African members from Lagos and three from Calabar in the Legislative Council.This was the first time Nigerians could choose their own representatives through voting.None of the earlier or later constitutions introduced this principle before 1922.Answer:Option B. Clifford Constitution of 1922.