This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Environment and health, Subject name: Social & Preventive Medicine
[{'content': 'Vegabond disease - \nSelect and explain. \nA. Louse, B. Mite, C. Tick, D. Black fly', 'role': 'user'}, {'content': "Answer: A \nExplanation: Lice are the vectors for the following diseases (Vagabond diseases) Epidemic typhus Relapsing fever Trench fever Dermatitis Park's Textbook of Preventive and Social Medicine, 25th edition, Page No. 837", 'role': 'assistant'}]