What should the third baseman do if the ball hits towards them and there is a runner on with no outs?

Being a third baseman in the MLB for the Brewers, if it is a weak ground ball, throw a hard throw to first base because the runner going to first has less of a boost to the base than the runner on first to second. If it is a rocket hit right at you, set your feet, and throw to second base to get the lead runner. If it is a line drive, catch it and throw to first (depending where the runner is). Most people are retards, and do not know what to do in this situation.

He should throw to the second baseman at second base.

Getting the runner at second is best because he is the lead runner. This is also the shorter throw.