Identify the recommendation you would make to a school district that is trying to structure its high schools to improve cognitive development

Cut the length of subject's periods from 40 minutes to 25 minutes so that
students do not have to pay attention for such a long time.
Enlarge schools so that students have more opportunities to find a group of
friends.
Create more opportunities for students to be involved in school clubs and
sports.
Discourage teachers and students from talking about personal matters by
separating teachers' lunchrooms, parking lots, and so on from those of
students.

Enlarge schools so that students have more opportunities to find a group of
friends.