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': 'Sleeping sickness is caused by \nSelect and explain. \nA. House fly, B. Sand fly, C. Tick, D. Reduvid bug', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]