Answer:
A. They emphasize the fact that Chief Joseph is going to speak candidly from the heart.
Step-by-step explanation:
This speech was made by Chief Joseph when he and his group was trying to scape for Canada, fleeing from the war and despair. Unfortunately, they can't make it, and under surrender, he uttered this speech, attesting American "humanity", and what he thought about that. The strength of this speech is exactly the tone. Chief Joseph used words carefully chosen, and straight from his heart, speaking about loyalty, freedom, care, and happiness, but especially the human tendency to destroy everything is important.