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
Actinomycosis is caused by: 
Select and explain. 
A. Fungus, B. Acid fast, non-motile bacillus, C. Anaerobic, gram positive, non-acid fast bacteria, D. Retrovirus
C: Anaerobic, gram positive, non-acid fast bacteria
Answer: C: Anaerobic, gram positive, non-acid fast bacteria 
Explanation: None