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.