Final answer:
Option B). The phrase references 'approaching enemies' during the Nez Perce retreat led by Chief Joseph as they were pursued by federal troops.
Step-by-step explanation:
The description of Chief Joseph's arrival by the words "Thunder rolling in the mountains sound of running feet" tells us how foes will approach. Within the historical backdrop, this is about the Nez Perce tribe, who were being followed by federal troops as they attempted to flee through the mountains to reach Canada. Chief Joseph led his people through difficult terrain throughout this retreat and was a strong voice against the abuse of his tribe; in the end, they surrendered just short of their objective to save more bloodshed.