Which events occurred before 1900 AD: (A) Establishment of seat of social medicine at Oxford, (B) Use of BCG vaccine, (C) Epidemiological work on cholera by John Snow, (D) Work on scurvy by james Lind
Answer is C. An english epidemiologist John Snow studied the epidemiology of cholera in London from 1848-1854 and established the role of polluted drinking water in spread of cholera.