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
Blood pressure level is an example of which of the following scales? 
Select and explain. 
A. Nominal, B. Ordinal, C. Metric, D. None of the above
C: Metric
Answer: C: Metric 
Explanation: 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