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
Drug of choice for diphtheria carrier is - 
Select and explain. 
A. Penicillin, B. Erythromycin, C. Procaine penicillin, D. Tetracycline
B: Erythromycin
Answer: B: Erythromycin 
Explanation: None