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 these are continuous variables except: 
Select and explain. 
A. Height in cms, B. Weight in kg, C. Blood groups A. B. ABO, D. Age in years and months
C: Blood groups A. B. ABO
Answer: C: Blood groups A. B. ABO 
Explanation: Ans: C. Blood groups A. B. ABORef High Yield Statistics/p13).Blood groups (A, B, ABO) is a discrete variable.