Entering the question right here and right now l

b.lincoln had the victory he wanted for emancipation

a. poison gas was sprayed over battlefields by airplanes to weaken enemy positions before major attacks.

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.