This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Medicine
[{'content': 'In rheumatic hea disease, infective endocarditis is detected by echocardiogram and the largest vegetations seen are due to - \nSelect and explain. \nA. Streptococcus viridans, B. Staphylococcus aureus, C. Candida albicans, D. Salmonella typhi', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref: R Alagappan - Manual of Practical Medicine 4th Edition.pg no:161-162 Acute infective endocarditis: Caused by highly virulent organisms mainly S. aureus (20-30%), seeding a previously normal valve 2D Echo * The smallest size of vegetation that can be picked up by echo is 2 mm. * Transoesophageal echocardiography is more sensitive in detecting vegetations in the aoic valve (90%) and mitral valve (100%) than transthoracic echocardiography', 'role': 'assistant'}]