What significant contribution did Franz Boas make to the field of anthropology?

Franz Boas is primarily recognized for his pivotal role in establishing cultural relativism as a foundational concept in anthropology. Cultural relativism asserts that a person's beliefs, values, and practices must be understood based on that person's own culture rather than be judged against the criteria of another culture. This perspective was revolutionary in the late 19th and early 20th centuries as it challenged the prevailing ethnocentric attitudes that often characterized scholarly thought at the time. Boas emphasized the importance of understanding cultural contexts and promoted the idea that cultures are diverse and dynamic. This approach has had a lasting impact on anthropological research and is fundamental in promoting an appreciation for cultural diversity.

The other options, while they may represent important aspects of anthropology, do not accurately capture Boas's unique contributions. He did not focus extensively on prehistoric cultures in the way suggested, nor was he known for developing quantitative research methods; rather, his work was more qualitative, focusing on ethnographic fieldwork. Additionally, while he did engage with ideas that relate to globalization, establishing this concept is not attributed to Boas specifically. His influence is most firmly embedded in the promotion of cultural relativism, making that the correct choice regarding his significant contributions to the field.