Final answer:
Source 5 is related to anthropology, reflecting the study of human societies and cultures, as evident from topics like origin stories and cultural diffusion.
Step-by-step explanation:
The question asks which subject Source 5 is related to, with options such as history, religion, linguistics, and anthropology. Considering the information provided, which includes topics on the history of sociology, origin stories, cultural diffusion through language and religion, and linguistic relativity, it is apparent that Source 5 is related to the subject of anthropology. Anthropology encompasses the study of human societies, cultures, and their development, which aligns with the topics mentioned in the excerpts. Based on the provided sources, Source 5 is related to the subject of History. In the given information, Source 5 mentions the topic of study in early sociology, which is connected to the development and understanding of societies throughout history.