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
An old lady had history of fall in bathroom once and could not move afterwards, she had led in externally rotated position, there was tenderness in scarpas triangle, no hip fracture was seen on x - ray, next step is 
Select and explain. 
A. CT, B. MRI, C. USCT, D. PET scan
B: MRI
Answer: B: MRI 
Explanation: None