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: Unknown
All of the following are Non-parametric test, except: 
Select and explain. 
A. Chi square test, B. Z test, C. Wilcoxon Rank sum test, D. Kruskal-Wallis ‘H’ test
B: Z test
Answer: B: Z test 
Explanation: None