Final answer:
Neanderthals lived in small bands of 15-50 people, which allowed them to survive in harsh conditions by ensuring mobility and effective leadership among group members.
Step-by-step explanation:
The prehistoric group that lived in bands of 15-50 people is C) Neanderthals. Neanderthals are well documented to have lived in small bands and are known for their strong physical build and ability to survive in cold climates during the ice age. Neanderthals lived in small bands of 15-50 people, which allowed them to survive in harsh conditions by ensuring mobility and effective leadership among group members.
They were primarily hunter-gatherers who congregated in these small groups, which facilitated easy mobility and effective leadership structures within their societies. These small group sizes were also beneficial for survival in the conditions of the Paleolithic Age, as large groups would have faced difficulties in securing enough food and resources.