The correct answer is A) speedy withdrawal.
The approach to decolonization that would best complete the diagram is speedy withdrawal.
After the scramble for Africa, where European powers split territories and colonized them in the African continent from 1880 to 1914, many of those European nations decided to left those African colonies for a varied of reasons. Some faster than others. A speed withdrawal meant that the European nation moved fast to left the place. This rapid exit left the African colony with social instability, economic problems, disparities, and obstacles to start reconstruction or a growing process.