The correct option is A Both A and R are true and R is the correct explanation of A.
Nigerian nationalism radicalised and grew in popularity and power in the post World War II period. It had the twin task of fighting the British and also welding the diverse and conflicting ethnic groups. There was a north-south divide. In addition to this, there was a divide between Igbos and Yorubas. Nigerian nationalism was supposed to unite all tribes, as it encouraged them to fight against British colonialism. However, the unification of Nigerian people fell short of expectations, and each region had its anti-colonial movement.