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': 'A special feature of the periodontal ligament fibroblasts is \nSelect and explain. \nA. The number of organelles, B. Presence of actin fibres and shape change, C. Size of the cells, D. Collagen fibre formation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]