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
Who is the "Father of Public health"? 
Select and explain. 
A. John snow, B. Robe Koch, C. Louis Pasteur, D. Cholera
D: Cholera
Answer: D: Cholera 
Explanation: Cholera is often called as the "father of Public Health"