posted by TOM .
Mrs. Carlson has discovered that the students in her class who watch a larger amount of television do more poorly on her exams compared to those who watch a smaller amount of television. Which of the following conclusions can Mrs. Carlson draw? Explain your answer.
a. Watching television causes students to do poorly on her exams.
b. Watching television causes students to spend less time studying, and the fact that they spend less time studying causes these students to do more poorly on the exams.
c. Doing poorly on exams causes students to watch television more frequently.
d. All of the above are probably valid.
e. None of the above conclusions is valid.