Utilize the input text as a context reference, choose the right relationship between Syriza and Alexis Tsipras from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

The new "preliminary draft" analysis of Greece's finances highlighted the deterioration that has taken place since Prime Minister Alexis Tsipras and his anti-austerity Syriza party took power at the beginning of 2015.

Answer: chairperson