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': 'Scattered diagram represents \nSelect and explain. \nA. Trend over time, B. Pie chart, C. Association between two variables, D. Frequencies telling occurrences', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]