A nutritionist wants to determine if a new diet plan affects cholesterol levels. She measures the cholesterol levels (in $\text{mg/dL}$) of $8$ patients before and after following the diet for three months. The data are as follows:

Using the Wilcoxon signed-ranks test at a $0.05$ significance level, test the claim that the matched pairs have differences that come from a population with a median equal to zero. Assume that the population of differences has a distribution that is approximately symmetric.

• A. There is sufficient evidence to support the claim that the matched pairs have differences that come from a population with a median greater than zero.
• B. There is insufficient evidence to support the claim that the matched pairs have differences that come from a population with a median greater than zero.
• C. There is insufficient evidence to warrant rejection of the claim that the matched pairs have differences that come from a population with a median equal to zero.
• D. There is sufficient evidence to warrant rejection of the claim that the matched pairs have differences that come from a population with a median equal to zero.

Answer: (C)