Identification of cholera by Snow is an example of?: (A) Spot map, (B) Random trial, (C) Analytical design, (D) Experimental design
Answer is A. <p> John Snow of England in his classic investigation of cholera epidemic in 1854 is an example of spot map. Park&;s textbook of preventive and social medicine,K.Park,23rd edition,page no:66 <\p>