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
Chancroid is caused by - 
Select and explain. 
A. H. ducreyi, B. T. pallidum, C. Gonococcus, D. HSV
A: H. ducreyi
Answer: A: H. ducreyi 
Explanation: None