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: Medicine
A patient of known valvular disease requires dental extraction. Pretreatment prophylaxis should be given with: 
Select and explain. 
A. Tetracycline 1000mg. one hr before surgery, B. Amoxicillin 3g orally one hour before, C. Amoxicillin 1g IM one hour before, D. Benzyl penicillin 12 lakh units 1 hour before
B: Amoxicillin 3g orally one hour before
Answer: B: Amoxicillin 3g orally one hour before 
Explanation: None