This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral Cavity, Subject name: ENT
All of the following lesions of the oral cavity are premalignant except- 
Select and explain. 
A. Erythroplakia, B. Hyperplastic candidiasis, C. Sideropenia, D. Aphthous ulcer
D: Aphthous ulcer
Answer: D: Aphthous ulcer 
Explanation: Ans. is 'd' i.e., Aphthous ulcer Lesions with increased risk of malignancy* Premalignant condition: - Leukoplakia, Erythroplakia, Speckled erythroplakia, chronic hyperplastic candidiasis.* Conditions increasing risk: - Oral submucous fibrosis, syphilitic glossitis, sideropenic dysphagia (Peterson Kelly syndrome).* Risk is doubtful: - Oral lichen planus, DLE, Dyskeratosis congenita.* Not premalignant:- Aphthous ulcers.