What factor do plessy v. ferguson, brown v. board of education, and regents of california v. bakke have in common?

Which statement best describes evidence of a mulitcultural mix in east africa? a. because of what he learned during his pilgrimage to mecca, mansa musa was able to build a center of islamic scholarship. b. the traders of ghana brought back with them slaves from the mediterranean who taught the ghana rulers about christianity. c. clans were made up of lineages that were descendants of multiple ancestors from different regions of africa. d. swahili became a language made up of words spoken by traders along the coast of the indian ocean.

Imagine you are driving down the highway and reading a sign that states save the planet don't litter which technique of policy enactment is being used

What are the most populous and least areas of russia and why are some areas more heavily populated than others