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
A elderly male patient presented with fever, chest pain and dry cough, sputum cultured on charcoal yeast medium, the organism is - 
Select and explain. 
A. H. influenzae, B. Moraxella cartarrhalis, C. Legionella, D. Burkholderia cepacia
C: Legionella
Answer: C: Legionella 
Explanation: None