How is the history of colonialism in Africa related to the currently failed states of Africa?
A. Colonialism created an import-based economy.
B. Colonialism created politically unstable nations.
C. Colonialism prevented migration to Africa.
D. Colonialism eliminated the need for slavery.

The highest point of a hill (or mountain) is a single point.
a single point can only be precisely marked with a dot. 
putting on a contour line is impossible  on a single point because the contour line is created after multiple points that have the same hight are marked, and after that, all of those points are connected with a line that creates a closed area. so the highest point, as said above, is a single point, there are no other points with the same height, so the only possible way for it to be marked is with a dot, and there is no possibility for a contour line.

If its a multiple choice answer as i believe it is the correct answer is c