During the era of the Rome Republic the power of the government came from ?

It all began when the Romans overthrew their Etruscan conquerors in 509 B.C.E. Centered north of Rome, the Etruscans had ruled over the Romans for hundreds of years. Once free, the Romans established a republic, a government in which citizens elected representatives to rule on their behalf.

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering

food chain i would say only because there is competition on getting food and survival