This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Spleen, Subject name: Surgery
Most common organism to cause OPSI 
Select and explain. 
A. Streptococcal pneumonia, B. H. influenza, C. Mycobacterium TB, D. Babesia
A: Streptococcal pneumonia
Answer: A: Streptococcal pneumonia 
Explanation: Ans (a) Streptococcal pneumoniaRef Sabiston page 1568/20th edition* 50-90% cases of OPSI is due to streptococcal pneumonia.* PPV23 vaccine is given nowadays 2 weeks prior to elective surgery