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': 'Degree of relationship between cause and effect is represented by \nSelect and explain. \nA. P value, B. Power of study, C. Risk ratio, D. Significance', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]