They were better off. Without the discovery of the uses of fire, mankind would not be here. Fire led to the rapid increase of newer, more advanced tech, such as a sword instead of a club.
Life. I think life is too short. I hate it.
In any energy pyramid, only 10% of the available energy is passed from one level to the next.
Hope this helps :D
I believe the answer is C, plz let me know if im wrong!