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: Social & Preventive Medicine
[{'content': 'Blood pressure level is an example of which of the following scales? \nSelect and explain. \nA. Nominal, B. Ordinal, C. Metric, D. None of the above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Metric scale: These are characteristics that can be measured in terms of a quantity. Duration of disease, haemoglobin level, hea rate and blood pressure are examples of such characteristics. Ref: Medical biostatistics, 1st edition pg: 99', 'role': 'assistant'}]