During assemblies at a particular high school, the gym is divided into four sections. Students sit in one of four sections according to their class (freshman, sophomore, junior, senior). In each section, there are many rows where students sit. 7. To estimate the proportion of students who enjoyed the assembly, members of student government randomly select 5 rows in the gym and survey each student in the selected rows. Which sampling method did the students use? a) Convenience sample b) Simple random sample c) Stratified random sample d) Cluster random sample e) Systematic random sample