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
Chi-square test tests: 
Select and explain. 
A. Standard error of Mean, B. Standard error of Propoion, C. Standard error of difference between 2 Means, D. Standard error of difference between Propoions
D: Standard error of difference between Propoions
Answer: D: Standard error of difference between Propoions 
Explanation: Standard error of difference between Propoions