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: Anatomy
Agent of Chancroid is 
Select and explain. 
A. H.influenzae, B. H.aegyptius, C. H.ducreyi, D. H.haemolyticus
C: H.ducreyi
Answer: C: H.ducreyi 
Explanation: Chancroid is an STD that presents as a genital ulcer. It is caused by H.ducreyi