Take context from the input text and decide on the accurate relationship between 'Syriza' and 'Alexis Tsipras' from the options provided.
Options: publisher, chairperson, location of formation, platform

ATHENS, Sept 20 The leftist Syriza party of Alexis Tsipras has won 35.07 percent of the vote in Greece's national election, according to data on the Interior Ministry website based on 10.16 percent of votes counted.
chairperson