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 of the following is an example of a nominal scale except - \nSelect and explain. \nA. Race, B. Sex, C. Body weight, D. Socio-economic status', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Weight is a quantitative variable, while a nominal scale is used for qualitative variables.', 'role': 'assistant'}]