It takes to much energy and there's a lot of dirt
C) Help with plant defense.
Many species are known to eat many plants, including flowers. To avoid being eaten, thorns in a rose bush help defend itself.
Volume? Is that what you mean?
I believe it would be manual labor. During the Industrial Age of Employment, most people would have to do repetitive jobs, or manual labor. Design, engineer, and knowledge broker were not common during this time.
