Joseph gives a math test to all the students in a middle school and notices that taller students have higher scores. He concludes that taller people are better at math. This conclusion is
A)
not justified, since the taller students could have cheated.
B)
justified, especially if it can be repeated on a second test.
not justified, since taller students have had more math in school
D)
justified, assuming that the test was given fairly to all students.