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 model of web of causation of diseases was first suggested by: 
Select and explain. 
A. Pettenkofer, B. Mac Mohan & Pugh, C. John M. Last, D. C.E.A. Winslow
B: Mac Mohan & Pugh
Answer: B: Mac Mohan & Pugh 
Explanation: None