Greece was a culination of many city states with different government systems. For example, Sparta was an oligarchy, and Athens was a democracy. Personally, I think this is a strange question because it doesn't specify which Greek society or in what context they believed this. Try looking in your reading, it may take a different specific viewpoint on this. If I had to give an answer, I would choose, B. They could run good governments. The governments that existed Greece are known for being revolutionary new developments.
Yes it completely makes it so third party candidates cannot become president. Presidential candidates who did not win a majority of the popular vote were elected president because of the electoral college. Presidential candidates mainly only campaign in swing states.