The children in the second grade at a local elementary school scored lower on tests of math skills this year than the second graders did last year. The school board blames the disappointing results on the budget cuts that forced the school to consolidate several classes of second-grade students, thus depriving them of the individualized attention that they had previously enjoyed. Which of the following, if true, best supports the explanation offered by the school board for the students' lower test scores? ['The test that the second graders took this year was not more difficult than the test that the second graders took last year.', 'Students at other elementary schools in the area also scored poorly on the same test of math skills this year.', 'No new textbooks were purchased by the school board this year.', 'Other schools in the area also experienced severe budget cuts.']