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
Incubation period of chancroid is: 
Select and explain. 
A. < 7 days, B. 10-14 days, C. 2-3 weeks, D. 3-4 weeks
A: < 7 days
Answer: A: < 7 days 
Explanation: Chancroid: caused by Hemophilus ducreyi Incubation period is 4 to 7 days Azithromycin is drug of choice Ref: Park 21st edition, page 305.