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': 'Early & established stage of gingivitis is differentiated by increase in number of \nSelect and explain. \nA. Plasma cells, B. Neutrophil, C. B-cell, D. Macrophages', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]