<prompt> Which of the following is not a risk factor for oropharyngeal carcinoma?Chronic hypertrophic candidiasisOral submucous fibrosisErythroplakiaNone of the above  <response>: Leukoplakia.Erythroplakia.Submucous fibrosis.Lichen planusLaryngeal keratosisActinic cheliosisSmooth,red tonque of plummer - vinson syndrome. 