2) a government agency produced a study in which they randomly chose 100 students just beginning college to determine what percentage of students who begin college graduate with a degree. after four years they identified that 23 had dropped out of college, 45 had graduated, and 20 were still pursuing their degree. what is wrong with this poll?
a. a nonresponse occurred.
b. this is a self-interest study.
c. some of the sample data are missing
d. the relationship between two variables implies one causes the other.