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': 'ANOVA is used: \nSelect and explain. \nA. To compare means in 2 groups, B. To compare means in 3 or more groups, C. To compare means in 1 group before and after intervention, D. To find correlation', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]