This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: FMGE 2019, Subject name: Pathology
[{'content': 'MC cause of atypical pneumonia? \nSelect and explain. \nA. Mycoplasma pneumoniae, B. Klebsiella pneumoniae, C. Hemophilus influenzae, D. Chylamydia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: MC cause of Atypical pneumonia- Mycoplasma Pneumoniae aka "Eaton\'s agent". This organism does not have cell wall which makes them resistant to the treatment by Penicillin\'s. The infection will be treated by the use of Macrolide antibiotic (Azithromycin).', 'role': 'assistant'}]