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
Xavier and Yogender stay in the same hostel of the same university. Xavier develops infection with Group B meningococcus. After a few days, Yogender develops infection due to Group C meningococcus. All the following are true statements except 
Select and explain. 
A. Vaccine prophylaxis of contacts of Xavier, B. Educate students about meningococcal transmission and take preventive measures, C. Chemoprophylaxis against both Group B and Group C, D. Vaccine prophylaxis of contacts of Yogender
A: Vaccine prophylaxis of contacts of Xavier
Answer: A: Vaccine prophylaxis of contacts of Xavier 
Explanation: No vaccine prophylaxis can be given to contacts of Xavier as there is no effective vaccine available for Group B Meningococcus.