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 labial bow in activator is constructed with: \nSelect and explain. \nA. 0.6mm, B. 0.5mrn, C. 0.7mm, D. 0.8mm & slightly heavier', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]