How did internal improvements make westward movement possible and somewhat easier?

aa dikha du tujhe mera wala dance

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.

because they can and they wanted to.

d the foreign governments