This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: School Health, Geriatrics, Subject name: Social & Preventive Medicine
[{'content': 'Gerontology is study of:- \nSelect and explain. \nA. Infants, B. Reproductive age group, C. Adolescents, D. Old age', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Gerontology: Study of physical and psychological changes seen in old age. Geriatrics/clinical gerontology: Care of the aged people. Social gerontology: Focus on social aspects, attitudes and problems of growing old. Experimental gerontology: Research into basic biological problems of ageing.', 'role': 'assistant'}]