I typed in Olympic Games and Olympia until I thought of Summer Olympic Games and even Summer Olympia. Too stupid for 'Summer Olympics'. (though the term is probably incorrect for 1896, as there were no 'Winter Olympics' back then).
Alexander The Great was the king of a Proto-Greek kingdom of Macedon, the modern nation known as the Former Yugoslav Republic of Macedonia (Correct Name for understanding) is inhabited by a offshoot of the Slavic people, closely related to modern Bulgarians, known as Slavic Macedonians, that settled in the north of Macedonia around the 7th Century and assimilated some of Macedonian Greeks. Confusion arises due to the government of FYROM cultural and historical misappropriation of key figures and symbols. This is common mistake though.
It actually is what they called the earth. The mythology didn't really have a specific name for a deity, but rather deities where the personification of a thing. This leads to the "names" of deities being the most literal description of the thing, because the "name" IS the thing it represents.
many other pointed out at Geo as not being the correct answer for earth. I too think so, and i want to add my explanation. The ancient greek word for earth has a two letters nominative "GI" (gamma-eta) which is then declined following the first greek declination. The theme vowel of the first declination are "A" (alpha) and "E/I" (eta) but NEVER "O" (omicron or omega). So GEO was definitely NOT the word ancient greeks used to refer to earth. We can see it used as a prefix, at most. GAIA or GEA are the (transliterated) name of earth's personification so would not be the correct answer as well but are closer to the original word than "geo". Personally, since translation and transliteration in this case are so confusing, i would substitute this question with another one like "the greek word for big" (answer: "mega"/"megas"; also "macro" could be accepted)
I would just accept different forms of Gaia because it literally means Earth, that's how names for many deities worked in ancient greece, whereas Geo is more of a prefix and derived from Gaia.