This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteriology, Subject name: Microbiology
Incubation period of Diptheria is 
Select and explain. 
A. 2 -6 days, B. 2 - 6 hours, C. 2 - 6 weeks, D. 2 - 6 months
A: 2 -6 days
Answer: A: 2 -6 days 
Explanation: The incubation period in diphtheria is commonly 3-4 days. In some cases sho as a day. In carriers, the incubation period may be very prolonged. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 240