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: Medicine
Chang staging is used for - 
Select and explain. 
A. Retinoblastoma, B. Medulloblastoma, C. Ewing's sarcoma, D. Rhabdomyosarcoma
B: Medulloblastoma
Answer: B: Medulloblastoma 
Explanation: None