i have trouble with the question at the bottom.

The NCAA survey includes this question: "When, if ever, did you start using anabolic steroids?" The response options are: have never used, before junior high, junior high, high school, freshman year of college, after freshman year of college. We focused on those who admitted use of steroids and compared the distribution of their responses for the years 1997, 2001, and 2005. (These are the years that the NCAA conducted the survey. Counts are estimates from reported percentages and sample size.) Recall that the NCAA uses random sampling in its sampling design. Initial Use of Anabolic Steroids 1997 2001 2005 Totals Junior high or before 16 15 69 100 High school 15 42 156 213 During freshman year of college 12 17 65 94 After freshman year of college 18 26 107 151 Totals 61 100 397 558 A test of homogeneity requires the comparison of the distribution of a single categorical variable across two or more populations (or subgroups). To run the test, we must have a random sample from each population. In this situation what are the populations and what is the categorical response variable? Does the data come from distinct random samples from the populations