To Use the Wilcoxon Rank Sum Test as a Test

Multiple Choice

To use the Wilcoxon rank sum test as a test for location, which of the following conditions must we assume?

A) that the obtained data are either ordinal or interval where the normality requirement necessary to perform the equal-variances t test ofis unsatisfied
B) that both samples are randomly and independently drawn from their respective populations
C) that both underlying populations from which the samples were drawn are equivalent in shape and dispersion
D) all of (a) , (b) , and (c)