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: Pathology
Point mutaton in which protooncogene is responsible for the development of gastrointestinal stromal tumor 
Select and explain. 
A. KIT, B. ALK, C. RET, D. FLT3
A: KIT
Answer: A: KIT 
Explanation: Ans. is 'a' i.e., KIT