The correct answer is D) cultural anthropologists.
When historians ask questions about variations across different groups of people with common traditions, they gather information from cultural anthropologists.
Cultural Anthropologists study the behaviors and traditions of people in different parts of the world. It focuses on the cultural differences between civilizations and between humans. Anthropologists have to spend days, weeks or month in the field, to study the behaviors of people, ask questions, and observe them on a daily basis.