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
Which one of the following bone tumors typically affects the epiphysis of a long bone - 
Select and explain. 
A. Osteosarcoma, B. Ewing's sarcoma, C. Chondroblastoma, D. Chondromyxoid fibroma
C: Chondroblastoma
Answer: C: Chondroblastoma 
Explanation: It occurs mostly in the epiphysis of long bones.