The student council at Eleanor Roosevelt High School is taking a survey of student opinions on this year's homecoming theme. To decide who to survey, the council creates a master alphabetized list of names from every student in the school, then selects every 20th student from the list. Will the results of this survey be valid? Why or why not?

yes, because a random sample is taken from all of the student body

yes, because the survey will include all of the seniors

no, because the survey will include freshman

no, because the survey will not include members of the faculty