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: Social & Preventive Medicine
Vagabond disease 
Select and explain. 
A. Louse, B. Mite, C. Tick, D. Black Fly
A: Louse
Answer: A: Louse 
Explanation: Ans. is 'a' i.e., Louse Vagabond's disease is pediculosis eorporis, caused by body louse.