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
Neutropenia is associated with : 
Select and explain. 
A. Nafcillin, B. Methicillin, C. Carbenicillin, D. Ampicillin
A: Nafcillin
Answer: A: Nafcillin 
Explanation: None