Rima wants to learn more about the heights of the students at Spring Valley Middle School. The school teaches students in grades 6 through 8. Each subject is taught by a different teacher, so students change classrooms every period. Students don't have a class every period, but every student has a homeroom class. Consider five samples from this population, then answer the questions that follow. Sample A: Survey four random students in each of Rima's classes. Sample B: Survey two random students from each homeroom class. Sample C: Survey three random girls from every third-period class. Sample D: Survey every sixth person in the student directory. Sample E: Survey every third person in the band directory.​