Suppose You Have the Following Hypothesis: Scores for Anxiety for a Single

Suppose you have the following hypothesis: Scores for anxiety for a single client will be lower during the treatment period than the one score taken for the baseline. What statistic would be appropriate for testing this hypothesis?

A) The independent t test which compares the scores of two groups of people.
B) The chi-square test which examines the relationship between two variables where each is measured at the nominal level.
C) The Spearman correlation which examines the relationship between two variables where each is measured at the ordinal level.
D) The one-sample t test which compares a set of scores with a single score.