This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
Mc Keon, in nineteenth century studied the decline in the incidence of the infectious diseases like tuberculosis and he explained the co-relation between the declinein the incidence of infectious disease and told that the relation is better understood in terms of - 
Select and explain. 
A. Increased awareness and knowledge, B. Social and economic factors, C. Behavioral interventions, D. Medical interventions
B: Social and economic factors
Answer: B: Social and economic factors 
Explanation: Thomas McKeown attributed the modern rise in the world population, AND DECLINE OF TB from the 1700's to the present to Broad economic and social changes (especially diet and nutrition- "Nutritional Determinism") rather than to targeted public health or medical interventions Ref: Internet