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: Pathology
[{'content': 'Lobar pneumonia is caused by: September 2010 \nSelect and explain. \nA. Staphylococcus aureus, B. Klebsiella, C. Streptococcus pnuemoniae, D. Pseudomonas', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: Streptococcus pnuemoniaeThe most common organism that causes lobar pneumonia is Streptococcus pneumoniae, also called the pneumococcus. Mycobacterium tuberculosis, the tubercle bacillus, may also cause lobar pneumonia if pulmonary tuberculosis is not treated promptly', 'role': 'assistant'}]