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
[{'content': 'The most frequent source of infection with Listeria monocytogenes is through which of the following? \nSelect and explain. \nA. Human feces, B. Livestock, C. Raw milk, D. Soil', 'role': 'user'}, {'content': 'Answer: C \nExplanation: .', 'role': 'assistant'}]