Concept:Hostility between Ibadan and Ijebu in the 19th century was driven by economic and military competition over access to the coast.
Explanation:Ibadan needed firearms and ammunition to carry out its military campaigns.
Lagos was the main coastal source of these goods.
Ijebu and Egba traders controlled the trade routes between Ibadan and Lagos.
Ibadan attempted to bypass these middlemen and buy arms directly from the coast.
This direct move threatened the commercial monopoly of Ijebu and Egba.
As a result, Ijebu blocked Ibadan's access and relations became hostile.
Thus, the root cause was Ibadan’s push to reach the coast for arms.
Answer:D. Ibadan’s attempt to reach the coast.