Enabling inheritance is a method that allows new subfolders to inherit the permissions and settings from their parent folder. If users can access files in the department share, but not in the new subfolders created by other users, it may indicate that inheritance is disabled and that each new subfolder has its own permissions and settings that restrict access to only the creator. Enabling inheritance can help resolve this issue by allowing all users to access the new subfolders with the same permissions and settings as the department share. Assigning share permissions, requiring multifactor authentication, and removing archive attribute are not methods that can most likely allow all users to access the new folders.