A psychologist measures stress levels on a standardized scale in $8$ patients before and after a mindfulness intervention. The results are:

Using the sign test or the Wilcoxon signed-ranks test, we can test for no difference between the stress levels before and after the mindfulness intervention. How does the Wilcoxon signed-ranks test differ from the sign test in terms of information used?

• A. The Wilcoxon signed-ranks test uses ties, whereas the sign test ignores them.
• B. The Wilcoxon signed-ranks test uses a parametric approach, while the sign test is non-parametric.
• C. The Wilcoxon signed-ranks test considers both the direction and the magnitude of the differences, while the sign test only considers the direction.
• D. The Wilcoxon signed-ranks test considers only the direction of the differences, while the sign test also incorporates the magnitude of the differences.

Answer: (C)