When Nigeria achieved full independence in 1960, they had already
established a federal political structure consisting of three regions based
on the three major population clusters that were in its borders.

(A) they had already established a federal political structure consisting
of three regions based on the three major population clusters that were in

(B) they already had established a federal political structure consisting
of three regions that was based on the three major population clusters inside

(C) they already had established a federal political structure that consisted
of three regions based on the three major population clusters in

(D) it had already established a federal political structure that consisted
of three regions based on the three major population clusters within

(E) it already had established a federal political structure consisting of
three regions being based on the three major population clusters it had within


QA after some discussion.