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': "Clicking of denture during speaking is due to \nSelect and explain. \nA. Increased vertical dimension of occlusion, B. Increased interocclusal space, C. Decreased vertical dimension of occlusion, D. Both 'B' & 'C'", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]