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: Dental
[{'content': 'Which of the following soft tissue responses may occur as a reaction to orthodontic bands? \nSelect and explain. \nA. Marginal gingivitis, B. Gingival fibrosis, C. Ulcerative gingivitis, D. Fulminating periodontitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]