<prompt> A variety of causative factors have been implicated in the development of Ca esophagus. Which of the following is NOT a predisposing factor for Ca esophagus?DiveiculaHuman papilloma virusMediastinal fibrosisCaustic ingestion  <response>: Etiologic Factors Believed to Be Associated with Esophageal Cancer: Excess alcohol consumption Cigarette smoking Other ingested carcinogens Nitrates conveed to nitrites Smoked opiates Fungal toxins in pickled vegetables Mucosal damage from physical agents Hot tea Lye ingestion Radiation-induced strictures Chronic achalasia Host susceptibility Human papillomavirus infection Esophageal web with glossitis and iron deficiency i.e., Plummer-Vinson or Paterson-Kelly syndrome Congenital hyperkeratosis and pitting of the palms and soles i.e., tylosis palmaris et plantaris Chronic gastric reflux i.e., Barretts esophagus for adenocarcinoma Esophageal diveicula Ref: Phan A.T. 2011. Chapter 17. Gastric and Esophageal Cancer. In H.M. Kantarjian, R.A. Wolff, C.A. Koller Eds, The MD Anderson Manual of Medical Oncology, 2e. 