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: Dental
The definition of Epidemiology as The study of the distribution and determinants of disease frequency in man was given by 
Select and explain. 
A. John M. Last, B. Winslow, C. MacMahon, D. Frost
C: MacMahon
Answer: C: MacMahon 
Explanation: None