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 karat of gold foil used for restoration is: \nSelect and explain. \nA. 22, B. 24, C. 16, D. 20', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Gold foil is made up of 24 karat gold.\nRef\xa0: Physical properties of dental materials pg 34', 'role': 'assistant'}]