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: Medicine
All are premalignant except - 
Select and explain. 
A. Arsenic poisoning, B. Zn deficiency, C. Utraviolent radiation exposure, D. Bowens disease
B: Zn deficiency
Answer: B: Zn deficiency 
Explanation: None