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: ENT
[{'content': 'All the following can cause mouth ulcers except ? \nSelect and explain. \nA. Sickle cell anemia, B. Lichen planus, C. Mouth washes, D. Psoriasis', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Psoriasis(lRef Dhingra &/e p. 217)", 'role': 'assistant'}]