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: Unknown
Which of the following organism is seen in a patient of left-sided endocarditis involving the mitral valve? 
Select and explain. 
A. Staphylococcus aureus, B. Streptococcus viridans, C. Enterococci, D. pseudomonas
B: Streptococcus viridans
Answer: B: Streptococcus viridans 
Explanation: Ans. BVegetations (arrows) due to viridans streptococcal endocarditis involving the mitral valve.