This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
The most common causative organism causing lobar pneumonia is 
Select and explain. 
A. Staphylococcus aureus, B. Streptococcus pyogenes, C. Streptococcus pneumonia, D. Hemophilus influenza
C: Streptococcus pneumonia
Answer: C: Streptococcus pneumonia 
Explanation: Although Streptococcus pneumoniae is most common, other organisms must also be considered in light of the patient&;s risk factors and severity of illness.(Ref: Harrison's 18/e p2131)