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
Bronchial hyperplasia may be caused by all except 
Select and explain. 
A. Smoking, B. Theophylline, C. Prematurity, D. Allergy
B: Theophylline
Answer: B: Theophylline 
Explanation: None