This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET 2019, Subject name: Pharmacology
DOC for prophylaxis against Diphtheria is:- 
Select and explain. 
A. Erythromycin, B. Rifampicin, C. Cloxacillin, D. Ciprofloxacin
A: Erythromycin
Answer: A: Erythromycin 
Explanation: Erythromycin is macrolide group of drug which binds irreversibly to a site on the 50s subunit of bacterial ribosome thus inhibiting translocation steps of protein synthesis. It is used to eliminate the carrier state of Corynebacterium Diphtheriae. Rifampicin: Blocks RNA transcription by interacting with B subunit of mycobacterial DNA dependent RNA polymerase.