Utilize the input text as a context reference, choose the right relationship between 'Syriza' and 'Alexis Tsipras' from the options.
Options: chairperson, legal form, business division, owner of

Prime minister Alexis Tsipras is also battling an internal revolt among his Syriza party over the recessionary measures he was forced to submit to in a July 13 agreement.
chairperson