The correct answer is D) competition among imperialist powers.
In the late nineteenth century, European imperialism in both Africa and China was characterized by fierce competition among imperialist powers.
These imperialists European superpowers, for instance, competed for the colonization and territorial presence in Africa, in what was known as the Scramble for Africa.
The competition was so high, the European nations decided to call the Berlin Conference from 1854 to 1855. The goal was to regulate their presence and colonization of Africa. We are talking about European superpowers of that time such as France, Germany, Great Britain, Belgium, Portugal, and Spain.
More than colonize and help African territories, Europeans were just interested in exploiting the many raw materials and natural resources in order to make big profits.