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
In a child with a pre-existing cardio valvular disease, antibiotic prophylaxis should be administered before a dental extraction so as to prevent: 
Select and explain. 
A. Bacterial endocarditis, B. Congestive cardiac failure, C. Pneumonia, D. Rheumatic carditis
A: Bacterial endocarditis
Answer: A: Bacterial endocarditis 
Explanation: Premedication with a systemic background

Patients with Subacute Bacterial Endocarditis - antibiotic prophylaxis is needed.
Patients with abscess - antibiotic therapy.

In a child with a pre-existing cardio valvular disease, antibiotic prophylaxis should be  administered before a dental extraction so as to prevent bacterial endocarditis.
Reference: Pediatric Dentistry SECOND EDITION, Shobha Tandon; page no 163