This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
[{'content': 'An investigator into the life expectancy of IV drug abusers divides sample of patients into HIV positive and HIV negative groups. What type of data does this division constitute - \nSelect and explain. \nA. Nominal, B. Ordinal, C. Interval, D. Poion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Scales can be: Qualitative: Categorical scales: Nominal : eg: names of countries . It&;s like naming or labeling . Dichotomous : eg: yes/no, presence/absence. Ordinal : severity of disease: mild/moderate/severe.eg: staging of cancer, kuppusamy socioeconomic class. Quantitative: Metric scales: Interval Ratio Note: Dichotomous is a subtype of nominal with 2 categories .', 'role': 'assistant'}]