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 single factor could contribute most of the\ndevelopment of simple gingivitis in children? \nSelect and explain. \nA. High fever, B. Poor oral hygiene, C. Oral habits, D. Physical nature of food ingested', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]