Concept:Colonialism in Nigeria began with a formal political takeover, not with religion or trade alone.
Explanation:Britain’s formal colonial presence started with the annexation of Lagos as a Colony in 1861.
This event marked the first official political control over Nigerian territory.
Christianity and economic adventurism were important earlier influences, but they only prepared the ground.
They did not, by themselves, establish colonial rule.
The indirect rule policy came much later, in the early 1900s, as an administrative method.
Therefore, the annexation of the Lagos Colony is the key event that opened Nigeria to actual colonial rule.
Answer:B. annexation of the Lagos Colony