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
All the following may be used in the prophylaxis of Meningococcal infection except - 
Select and explain. 
A. Penicillin, B. Sulphonamides, C. Erythromycin, D. Rifampicin
C: Erythromycin
Answer: C: Erythromycin 
Explanation: None