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: Ophthalmology
A 10 year boy present with b/l chronic uveitis. Which investigation should be ordered: 
Select and explain. 
A. Hemogram, B. X-ray of sacroiliac joint, C. HIV rest, D. Mantoux test
D: Mantoux test
Answer: D: Mantoux test 
Explanation: Ans. Mantoux test