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: Pharmacology
Doxycycline is used in the treatment of the following diseases? 
Select and explain. 
A. Leptospirosis, B. Q fever, C. Borreliosis, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: None