Which of the following best describes how to use a test-retest reliability estimate to assess reliability?
a) administer a test with content based on what a person actually needs to know to effectively perform the job in question
b) administer different tests to a group of people and compare the range of collected test scores
c) administer the same test to the same people at two different points in time and compare their test scores at time 2 with their scores at time 1
d) administer the same test to different people at two different points in time and compare their test scores at time 2 with the scores at time 1