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
After the appearance of rash, prophylactic isolation of measles case is necessary for a minimum of:September 2007 
Select and explain. 
A. 2 days, B. 5 days, C. 7 days, D. 9 days
B: 5 days
Answer: B: 5 days 
Explanation: Ans. B: 5 days