This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Anatomy
[{'content': 'Least chances of infective endocarditis is associated with: \nSelect and explain. \nA. Mild MS, B. Mild MR, C. Small ASD, D. Small VSD', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Infective endocarditis is very rare in patients of ostium secondum atrial septal defect, unless floopy mitral valve is present .(ref Ghai 7th/390,403)', 'role': 'assistant'}]