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
All of the following is an example of a nominal scale except - 
Select and explain. 
A. Race, B. Sex, C. Body weight, D. Socio-economic status
C: Body weight
Answer: C: Body weight 
Explanation: Weight is a quantitative variable, while a nominal scale is used for qualitative variables.