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': 'Cutting and grinding procedures are predominantly: \nSelect and explain. \nA. Two directional, B. Unidirectional, C. Three directional, D. Multidirectional', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]