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 minimum amount of fluoride that should be present in salt for effective anticaries activity in: \nSelect and explain. \nA. 3mg of F/5gm of salt, B. 1.5mg of F/5gm of salt, C. 10mg of F/5gm of salt, D. 100mg of F/5gm of salt', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]