In the context of the input sentence, determine the relationship between 'Syriza' and 'Athens'.
Options: developer, headquarters location, chief executive officer, operator

The Athens General Index (.ATG) has fluctuated sharply this year, which has seen left-wing Prime Minister Alexis Tsipras's newly elected Syriza government wrangle with European Union and International Monetary Fund lenders in bitter bailout talks.
headquarters location