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: Social & Preventive Medicine
Which of the anti-microbials is the drug of choice for prophylaxis of meningococcal meningitis? 
Select and explain. 
A. Ciprofloxacin, B. Rifampicin, C. Penicillin, D. Gentamycin
B: Rifampicin
Answer: B: Rifampicin 
Explanation: Rifampin is effective against many gram positive and gram-negative microorganisms. It is the drug of choice for prophylaxis of meningococcal meningitis. Rifampin is used prophylactically in close contacts of patients affected by epiglottitis or meningitis caused by Haemophilus influenza. The drug also used prophylactically against leprosy and in combination with other drugs to treat Legionella.