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': 'Periodontal ligament has predominantly: \nSelect and explain. \nA. Type II collagen fibres, B. Oxytalan fibres, C. Elastic fibres, D. Type I collagen fibres', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]