This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pathology
[{'content': 'Which of the following markers is specific for gastro-intestinal stomal tumor (GIST) \nSelect and explain. \nA. CD117, B. CD34, C. CD23, D. S-100', 'role': 'user'}, {'content': 'Answer: A \nExplanation: most useful diagnostic marker of GIST is is c-KIT or CD117 REF :SYSTEMIC AND GENERAL PATHOLOGY RAMDAS NAYAK 2ND EDITION PAGE NO:390 Refer robbins 9/e', 'role': 'assistant'}]