Which of the Following Tests Would Be an Example of a Non-Parametric

Short Answer

Which of the following tests would be an example of a non-parametric method? $\begin{array}{|l|l|}\hline A&\text {Wil coxon signed rank sum test. }\\\hline B&\text {Kruskal-Wallis test. }\\\hline C&\text { Friedman test.}\\\hline D&\text { All these choices are correct.}\\\hline \end{array}$