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: Pharmacology
Acid susceptible penicillin is? 
Select and explain. 
A. Methicillin, B. Ampicillin, C. Amoxicillin, D. Cloxacillin
A: Methicillin
Answer: A: Methicillin 
Explanation: None