What can you conclude from this, assuming that the geocentric model holds that the sun, moon, and planets like mars all orbit around earth in simple circles?

For starters this is untrue. It is the point of view the people had till few hundred years ago about the Solar System though. From there perspective the Earth was the center of the universe, and also the biggest body, so all the others were orbiting around it. So going by that assumption, for that to happen in practice, the Earth should be the biggest of all bodies in our Solar System, to have the most mass by far, thus having the strongest gravitational pull by far, so that the other bodies orbit around it, like the Moon does in practice.

Ithink its b but i'm not sure.

The first immigrants to settle in what is now the united states were the ancient ancestors of modern native americans. the precise routes of those first north american immigrants are disputed, but there is no uncertainty about the fact that every human being on the continent is either a recent immigrant or a descendant of earlier immigrants. since the first immigrants came here from asia more than thirteen thousand years ago, there have been four large and easily recognizable modern waves of immigrants into the united states.