The given sentence is missing in the paragraph below. Decide where it best fits among the options 1, 2, 3, or 4 indicated in the paragraph.

"Everything is old-world, traditional techniques from Mexico," Ava emphasizes. The sisters embrace the ways their great-grandfather built and repaired instruments. (1) When crafting a Mexican guitarrón used in mariachi music, they use tacote wood for the top of the instrument. Once the wood is cut, they carve the neck and heel from a single block using tools like hand saws, chisels and sandpaper rather than modern power tools and believe that this traditional method improves the tone of the instrument. (2) Their store has a three-year waitlist for instruments that take months to create. (3) The family's artisanship has attracted stars like Los Lobos, who own custom guitars made by all three generations of the Delgado family. (4) For the sisters, involvement in the family business started at an early age. They each built their first instruments at age 9.

What was the occupancy factor for segment D-E?

The ratio of the number of students in the morning shift and afternoon shift of a school was 13 : 9. After 21 students moved from the morning shift to the afternoon shift, this ratio became 19 : 14. Next, some new students joined the morning and afternoon shifts in the ratio 3 : 8 and then the ratio of the number of students in the morning shift and the afternoon shift became 5 : 4. The number of new students who joined is