Prime Minister Alexis Tsipras resigned last week after his acceptance of an 86 billion euro ($96 billion) rescue package for Greece's stricken economy triggered a major rebellion within his radical left Syriza party.
Refer to the input text as context and select the correct relationship between 'Syriza' and 'Alexis Tsipras' from the available options.
Options: owned by, currency, chairperson, headquarters location