Im sure it was mainly the idea of humanism. It changed the way people saw education, from knowledge to preparation for life. The humanist idea also bought upon the significance of the human body. Used within paintings and sculptures, a new idea of art was introduced completely
Different customs led to many disagreements and skirmishes. The Powhatan tribe was very distrustful of the white settlers and for good reason. The European settlers were actually trying to push natives off their rain so that they could claim it for themselves.
If we are talking about the second world war, then then answer would be that the Chinese kept the Japanese busy fighting them, and in turn, about 800,000 of their troops. This gave the Americans, who were the main force against the Japanese during this time, a little breathing room with which to continue military operations.
Hope this answered your question.
C, they were always using their surroundings to harvest food and resources.