Not necessary, because the author never describes what specific aspects of long breaks are not in childrens’ interest. So even if children don’t tend to forget what they have learned during long breaks, there can still be other reasons a long break is not ideal for children.

The argument is based on what’s true about most people, who don’t live an agricultural life. So what’s true about children who do have an agricultural life has no impact on the argument.

Not necessary, because the author never suggests any specific replacement for a school calendar with long breaks. We have no idea what the author believes is appropriate for the school calendar other than that long breaks should be removed.

The argument is based on what’s good for the interests of children. It’s not based on what’s going to serve the interests of agricultural life.

Necessary, because if it were not true — if a school calendar without long breaks would NOT serve the interests of children more than a school calendar with long breaks — then we have no reason to think that long breaks should be removed from the school calendar. Going without long breaks would be EQUAL or WORSE compared to having long breaks when it comes to children’s interests.