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
In MEN syndromes 2A and 2B, which growth factor receptor shows point mutation? 
Select and explain. 
A. TP53, B. RET, C. KIT, D. MSH 2
B: RET
Answer: B: RET 
Explanation: None