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: Microbiology
Infective dose of S.typhi is 
Select and explain. 
A. 10 bacilli, B. 102 bacilli, C. 103-106 bacilli, D. 107-1012 bacilli
C: 103-106 bacilli
Answer: C: 103-106 bacilli 
Explanation: Infective dose is 103-106 colony forming units.