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
[{'content': "Ito's test is used in the diagnosis of the following infection: \nSelect and explain. \nA. Gonorrhoea, B. Herpes, C. Chancroid, D. Granuloma venereum", 'role': 'user'}, {'content': "Answer: C \nExplanation: The Ito Reenstierna test was developed for detecting Haemophilus ducreyi using a commercial antigen by intradermal testing and proved positive in 90% of cases. Gram staining shows 'school of fish' or 'railroad track' appearance which is characteristic. Nucleic acid amplification tests are now the optimal method of diagnosing H. ducreyi. Ref: Oxford Textbook of Medicine: Infection edited by David Warrell, Timothy M. Cox, John Fih, Estee Torok, 2012, 375-376.", 'role': 'assistant'}]