This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal system, Subject name: Anatomy
CD-99 is for 
Select and explain. 
A. A. Ewing's sarcoma, B. B. Sll, C. C. Dermatofibroma protrubens, D. D. Malignant histocytic fibroma
A: A. Ewing's sarcoma
Answer: A: A. Ewing's sarcoma 
Explanation: CD 99 is a marker associated with the diagnosis of Ewing's sarcoma Granulosa cell tumor is also often found to be associated to CD 99