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': 'All the following are examples of nominal scale except- \nSelect and explain. \nA. Race, B. Sex, C. Iris color, D. Blood pressure', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Nominal scale is used for qualitative data.\n\nBlood pressure is quantitative data, which is used on the ratio scale.\nRace, sex and Iris color are\xa0qualitative data.', 'role': 'assistant'}]