A Particular Additive Is Claimed to Increase the Fuel Efficiency

Multiple Choice

A particular additive is claimed to increase the fuel efficiency of hybrid vehicles. Eight hybrid cars are used to determine if there is a difference in fuel efficiency (l/100km) with and without the additive. The appropriate nonparametric method to use for these data is the

A) Kruskal-Wallis test.
B) Kendall's tau test.
C) Wilcoxon signed-rank test.
D) Wilcoxon rank-sum test.
E) Spearman's rho test.