What is the relationship between 'Syriza' and 'Alexis Tsipras' in the context of the input sentence.
Options: chairperson, currency, legal form, publisher

Prime Minister Alexis Tsipras and his ruling Syriza party's major issue with bailout proposals so far has been that they effectively turn Greece into a zombie country, stumbling along the poverty line and existing solely to pay off its heavy debts.
chairperson