Educator: Reducing class sizes in our school district would require hiring more teachers. However, there is already a shortage of qualified teachers in the region. Although students receive more individualized instruction when classes are smaller, education suffers when teachers are underqualified. Ttherefore, reducing class sizes in our district would probably not improve overall student achievement. Which one of the following is an assumption required by the educator's argument? ["Qualified teachers could not be persuaded to relocate in significant numbers to the educator's region to take teaching jobs.", 'Students place a greater value on having qualified teachers than on having smaller classes.', 'At least some qualified teachers in the school district would be able to improve the overall achievement of students in their classes if class sizes were reduced.', 'Class sizes in the school district should be reduced only if doing so would improve overall student achievement.']