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
Drug of choice in pertussis is : 
Select and explain. 
A. Penicillin, B. Doxycycline, C. Erythromycin, D. Ciprofloxacin
C: Erythromycin
Answer: C: Erythromycin 
Explanation: None