This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of health and disease, Subject name: Social & Preventive Medicine
Theory of contagion was first given by 
Select and explain. 
A. Paracelsus, B. Fracastorius, C. Vesalius, D. Pare
B: Fracastorius
Answer: B: Fracastorius 
Explanation: Fracastorius, an Italian physician enunciated the 'theory of contagion'. He envisaged the transfer of infection minute invisible paicles and explained the cause of epidemics. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 5