A primary school applied to the local education administration for the purchase of an additional school bus to strengthen the ability to transfer teachers and students. The education administration rejected this application on the grounds that the number of school buses must be proportional to the size of the school and the number of teachers and students According to the school's current number and scale of teachers and students, the existing school bus is sufficient. Which of the following assumptions best supports the decision of the education administration? ['Survey shows that renting a school bus is more economical than buying a school bus.', 'There will be no vehicles scrapped at least in the near future.', 'The number of primary school-age children in the region will not increase significantly in the future.', "The education administration has no plan to expand the school's teachers and students."]