This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
The most frequent source of infection with Listeria monocytogenes is through which of the following? 
Select and explain. 
A. Human feces, B. Livestock, C. Raw milk, D. Soil
C: Raw milk
Answer: C: Raw milk 
Explanation: .