This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': 'Which of the following markers is specific for gastro intestinal stromal /tumors (GIST)? \nSelect and explain. \nA. CD 117, B. CD34, C. CD23, D. S-100', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Marker in GIST CD117-( c-kit)- 95% CD34-70% Smooth muscle Actin-5%', 'role': 'assistant'}]