Task: Question Answering
Input (English): Passage: In the late 19th century, three European-American middle-class female teachers married Indigenous American men they had met at Hampton Institute during the years when it ran its Indian program. In the late nineteenth century, Charles Eastman, a physician of European and Sioux ancestry who trained at Boston University, married Elaine Goodale, a European-American woman from New England. They met and worked together in Dakota Territory when she was Superintendent of Indian Education and he was a doctor for the reservations. His maternal grandfather was Seth Eastman, an artist and Army officer from New England, who had married a Sioux woman and had a daughter with her while stationed at Fort Snelling in Minnesota. Question: What tribe was Eastman related to?
Output (English): Sioux