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: Orthopaedics
A 6 year old boy presents with painful limp. On clinical examination, tenderness in femoral triangle and some limitation of Hip movements. X-ray is normal, Next investigation 
Select and explain. 
A. MRI, B. CT scan, C. Arthroscopy, D. Bone scan
A: MRI
Answer: A: MRI 
Explanation: None