Final answer:
Dr. Rosensweig is studying the language of the Asante people, which is a focus within the field of linguistic anthropology.
Step-by-step explanation:
Dr. Rosensweig, who studies the speech patterns that the Asante people use to communicate, is focusing on an area of linguistic anthropology. The correct answer to the student's question is c. Language. This field is concerned with how language affects our thinking and the production of human culture, including the study of different categories of speech in both everyday activities and ritualized contexts. It involves the in-depth analysis of spoken language to understand social actions and cultural norms.