The data show that after the implementation of the "No Child Left Behind" Act, the average scores of English reading subjects and math subjects in fourth and eighth-grade students have indeed improved significantly. Therefore, it is concluded that this education reform bill Elementary school has made amazing achievements. Which of the following, if true, would be the least sceptical of the above argument:. ["Grade 12 students 'English reading subjects' average scores have declined significantly during the same period.", 'It is only one-sided to focus only on changes in English reading and math performance and use it as a marker for evaluating the results of education reforms.', 'It is really difficult to improve the education system. To make changes in this hugely inert bureaucracy requires a lot of money, effort and time.', 'The average reading scores of English reading subjects and mathematics subjects for fourth and eighth-grade students have been increasing by the same proportion year by year since the 1990s. This situation appeared long before the bill was passed.']