The correct answer is - in the north of the country.
Greece is a country that in general, around 70%, is not suitable for agriculture because of the poor soil and lack of water. The regions in the northern part of the country, Macedonia and Thrace, are the only suitable places for agriculture. In these two regions the soil is fertile, there's multiple streams and rivers, so the people started using it for creating farmlands. Greece produces a large number of agricultural products, most of which are olives, grapes, tomatoes, oranges, tangerines, tomatoes, sugar beet, large portion of which are for export.