Refer to the input text as context and select the correct relationship between 'Syriza' and 'Athens' from the available options.
Options: developer, chief executive officer, operator, headquarters location

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