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: Microbiology
Who has coined and developed the concept 'Theory of web of causation'? 
Select and explain. 
A. Mc Mohan and Pugh, B. Pettenkoffer, C. John snow, D. Louis Pasteur
A: Mc Mohan and Pugh
Answer: A: Mc Mohan and Pugh 
Explanation: "The web of causation theory was given by MC Mohan and Pugh". It is based upon the epidemiological triad of: Agent Host Environment Ref: Park's Textbook of Preventive and Social Medicine, 20 th edition, Page 32.