0905 : Far-left members of Greece's ruling Syriza party have revealed plans to form a splinter party, Popular Unity, following the resignation of Prime Minister Alexis Tsipras and calling of snap elections overnight.
Take context from the input text and decide on the accurate relationship between 'Syriza' and 'Alexis Tsipras' from the options provided.
Options: product/material produced, employer, chairperson, chief executive officer