This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Orthopaedics
A 7-year-old boy with h/o trauma 2 months back now presents with fever and acute pain over thigh. On X-ray femoral shaft shows lesions with multiple laminated periosteal reaction next line of management: 
Select and explain. 
A. CRP measurement, B. Core biopsy, C. Tc99 MDP scan, D. MRI
D: MRI
Answer: D: MRI 
Explanation: (d) MRI- Information in this question are: 1st Decade, diaphyseal lesion with onion peel reaction goes towards Ewing's sarcoma. Next best investigation is MRI for soft tissue involvement, marrow involvement and micrometastasis. Overall the best investigation is Biopsy to confirm the diagnosis but MRI is done before the biopsy, to localize the best site for biopsy.