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': 'Pigmentation of chemicals in mucosa is due to \nSelect and explain. \nA. Increased permeability of blood vessels, B. Local deposition of chemicals in mucosa, C. Sub epithelial precipitation in connective tissue at the site due to increased capillary permeability, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]