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: Surgery
Smoking increase the risk of all of the following cancer's, except: 
Select and explain. 
A. Ca Larynx, B. Ca Nasopharynx, C. Ca Bladder, D. Ca Esophagus
B: Ca Nasopharynx
Answer: B: Ca Nasopharynx 
Explanation: Role of smoking and development of nasopharyngeal carcinoma is still not clear. Ref: Diet, Nutrition and Cancer: Proceedings of The 16th International Symposium on Mycotoxins By Takamatsu No Miya, Page 51; Carcinomas of The Head and Neck: Evaluation and Management By Charlotte Jacobs, Page 275; Cancer Prevention: The Causes and Prevention of Cancer By Graham A. Colditz, David John Hunter, Page 327