Final answer:
A paired t-test is suitable for examining the effects of a treatment on a single group over time, as this implies dependent samples where measurements are taken from the same subjects under different conditions. The correct option is (C).
Step-by-step explanation:
For which of the following extensions to the aforementioned study would a paired t-test be appropriate? The option that is suitable for a paired t-test is (c) Examining the effects of a treatment on a single group over time.
A paired t-test is used when comparing two related samples or matched pairs to determine if there is a statistically significant difference between two sets of observations.
This is typically done by measuring a single sample of participants twice under different conditions, or by having a sample of matched participants where each pair is similar in terms of specific control variables.
In other words, a paired t-test is appropriate when you are dealing with dependent samples, and option (c) deals with a time-based treatment on the same group, meaning there is a dependency in the measurements (pre-test and post-test are on the same subjects).