Why did the Sauk and Ojibwe choose to invite the British soldiers to Fort Michilimackinac on that particular date? What were their feelings toward British presence in their land?

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.