Take context from the input text and decide on the accurate relationship between 'Syriza' and 'Alexis Tsipras' from the options provided.
Options: business division, distribution format, member of, chairperson

ATHENS, Greece — Alexis Tsipras is set to receive the formal mandate later Monday to form a Greek government for the second time, after his left-wing Syriza party unexpectedly won a decisive victory in early national elections.
chairperson