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: Dental
[{'content': 'In a child with a pre-existing cardio valvular disease, antibiotic prophylaxis should be administered before a dental extraction so as to prevent: \nSelect and explain. \nA. Bacterial endocarditis, B. Congestive cardiac failure, C. Pneumonia, D. Rheumatic carditis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Premedication with a systemic background\n\nPatients with Subacute Bacterial Endocarditis - antibiotic prophylaxis is needed.\nPatients with abscess - antibiotic therapy.\n\nIn a child with a pre-existing cardio valvular disease, antibiotic prophylaxis should be\xa0 administered before a dental extraction so as to prevent bacterial endocarditis.\nReference: Pediatric Dentistry SECOND EDITION, Shobha Tandon; page no 163', 'role': 'assistant'}]