Kai is conducting a study about the percentage of students with jobs. his school has 2500 students. he asks everyone in his drama class to participate in a survey. he bases his findings on these results. is this a valid study? why or why not?

a) yes, he asked everyone in his class.
b) yes, since drama students tend to have after-school jobs.
c) no, he should have taken a small sample from the drama class.
d) no, the drama class does not represent all students in the school.