参考答案

正确答案：C
解析：根据题干关键词Dr．Weeks，function定位到原文第四分标题下第五句：“People often save，'Oh，sleep is sleep,' but sleep is life-saving．It's restorative,” Dr．Weeks says．可知睡眠有助于恢复健康，延长寿命。故C项符合文意。