Refer to the input text as context and select the correct relationship between 'Syriza' and 'Alexis Tsipras' from the available options.
Options: manufacturer, developer, chairperson, founded by

The new "preliminary draft" analysis of Greece's finances highlighted the deterioration that has taken place since Prime Minister Alexis Tsipras and his anti-austerity Syriza party took power at the beginning of 2015.
chairperson