What is an example of a Sphere of influence

Which fact would this be, and how might you verify the truth?

European imperialism in the 19th century was largely motivated by a desire to: o a. assert power over other parts of the world. b. end the racist policies practiced in many foreign countries. o c. defend europe from aggressive foreign armies. d. relocate ethnic and religious minorities within national borders.

The 15th amendment to the u. s. constitution, ratified in 1870, deals with what issue? a. prohibition of alcohol b. voting c. declaring war d. free speech