Why was the struggle for civil rights more difficult because of the “separate but equal” doctrine established in the Plessy v. Ferguson case?

answer is b.

  it is always the best policy to have good communication and good relations between individuals and, specially, between leaders of the countries. for this purpose, among others, there is a common place, the united nations, where the representants can present his and learn about the other country's policies.

napoleon the third became a empire in 1873 also known as the era of the franco-prussian war.