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': 'The following is/are a rich source of fluoride: \nSelect and explain. \nA. Dried fish, B. Tea leaves, C. Cabbages, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The dried tea leaves contain 100-400 ppm fluoride, depending on the brand.\nFish products, in particular canned fish such as salmon and sardines have a fluoride content of up to 20-40 mg/kg. The meat of fish is relatively low in fluoride content (2-5 mg/kg) as compared with fish protein concentrates, which may contain up to 370 mg/kg.\nCertain plants, such as taro, yams, and cassava, cabbage have been found to contain relatively high fluoride levels.\nEssentials of preventive and community dentistry\nSoben Peter\n5th edition\npage no. 243', 'role': 'assistant'}]