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: Microbiology
The time gap between appearance of koplik's spot and cutaneous rash in measles is: 
Select and explain. 
A. 24 Hrs, B. 3-4 days, C. 2 weeks, D. 10 days
B: 3-4 days
Answer: B: 3-4 days 
Explanation: None