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: Skin
A 29 years old male with a history of long leisure trip presented with right knee pain and swollen join with foreign 
Select and explain. 
A. Sarcoidosis, B. Tuberculosis, C. Reiter's disease, D. Bechet's disease
C: Reiter's disease
Answer: C: Reiter's disease 
Explanation: C. i.e. Reiter's disease