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.

Greek PM Tsipras under pressure over covert Syriza drachma plan reports 34 minutes ago Greek Prime Minister Alexis Tsipras in Athens, Greece July 24, 2015.

Answer: chairperson