This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
[{'content': 'Common age for otosclerosis is - \nSelect and explain. \nA. 5-10 yrs, B. 10-20 yrs, C. 20-30 yrs, D. 30-45 yrs', 'role': 'user'}, {'content': 'Answer: C \nExplanation: 50% of patients of otosclerosis have positive family history.\nFemales are more commonly affected than males. (Note: unless and until the question says in India always mark female> male as the correct option).\nWhites are affected more than negroes.\nAge = most common between 20–30 years (Ans. 3) and is rare before 10 and after 40 years.\nDeafness is increased by pregnancy, menopause, trauma and major operations.\nViruses like measles virus have also been associated with it.', 'role': 'assistant'}]