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: Gynaecology & Obstetrics
[{'content': 'True about chancroid is \nSelect and explain. \nA. Incubation period is 3 to 10 weeks., B. Characterised typically by prodromal symptoms and systemic reaction., C. Painful ulcer with irregular erythematous non-indurated margins., D. Ulcer base is hard, indurated.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Chancroid:\n\nIncubation period = 3 to 10 days\nIt lacks systemic reaction and prodrome.\nUlcer base is soft.', 'role': 'assistant'}]