A group of college students believes that herbal tea has remarkable restorative powers. To test their belief, they visit a local nursing home, visiting with and talking to the residents while serving them herbal tea. After several weeks of this, the nursing home staff reports that the residents are healthier and more cheerful. The subjects in this experiment areA) the nursing home staff. B) the nursing home residents. C) the brands of herbal tea. D) the college students.