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': 'Function of wetting agents used in casting procedure is \nSelect and explain. \nA. To felicitate wetting of ring liner, B. To felicitate mixing investment, C. To reduce contact angle of a liquid with wax surface, D. For better wax elimination', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]