This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous System, Subject name: Radiology
Radiological sign of spondylolysis? 
Select and explain. 
A. Napoleon's hat sign, B. 'Scottish dog with collar' sign, C. Winking owl sign, D. 'Cap' sign
B: 'Scottish dog with collar' sign
Answer: B: 'Scottish dog with collar' sign 
Explanation: Ans BIn spondylolysis on oblique view scotty dog with collar is seen while in spondylolisthesis inverted napoleon hat sign (AP view L5 over S1) and scotty dog with broken neck sign (oblique view) are seen.