Answer:
Option B: Paired sample t-test, since there is a "before 20 push ups" and "after 20 push up " score for each participant.
Explanation:
In this question, we have a case where each participant undergoes different exercises to see differences before and after 20 push ups.
Now, it's obvious that the same condition applies to all participants i.e. differences before and after 20 push ups.
Thus, this will be a case of paired sample t-test or dependent t test because conditions for all participants in both tests are dependent or same.
So, the only option that corresponds with my explanation to use paired sample is option B