Refer to the input text as context and select the correct relationship between 'Syriza' and 'Alexis Tsipras' from the available options.
Options: location of formation, director/manager, chairperson, business division

Greece's government on Tuesday submitted tough bailout terms demanded by eurozone creditors to parliament, as Prime Minister Alexis Tsipras battled for support for the draconian reforms from his ruling anti-austerity Syriza party.
chairperson