An effect of the diseases that were part of the Columbian Exchange was that:
O
A. Africans brought to America lacked natural protection to disease.
O
B. Native American populations returned to their original size after
years of exposure to disease.
O
C. Europeans settling in American lacked natural protection to
disease
D. Europeans took advantage of Native American societies
weakened by disease.

Europeans brought deadly viruses and bacteria, such as smallpox, measles, typhus, and cholera,

option D. i think sorry if its wrong..

Explanation:

hope this helps!

cuba is a multi-ethnic nation

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.