This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pneumonia, Bronchiectasis, and Lung Abscess, Subject name: Medicine
[{'content': 'The most common causative organism for lobar pneumonia is: \nSelect and explain. \nA. Staphylococcus aureus, B. Streptococcus pyogenes, C. Streptococcus pneumoniae, D. Haemophilus influenzae', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C. Streptococcus pneumoniaeThe most common organisms which cause lobar pneumonia are Streptococcus pneumoniae, also called pneumococcus. MC typical pneumonia: strept. pneumonia* MC of atypical pneumonia: Mycoplasma* MC nosocomial pneumonia: gram negative bacilli* MC early VAP: Streptococcus* MC late VAP: pseudomonas* MC VAP: pseudomonas* MC pneumonia in cystic fibrosis: pseudomonas* MC pneumonia resulting in ICU admission: streptococcus* MCC pneumonia in HIV: tuberculosis* MC pneumonia in smokers: Strept. pneumonia* MC trigger for asthma exacerbation: Rhinovirus.* MC cause exacerbation of COPD: H. influenza', 'role': 'assistant'}]