Greek Prime Minister Alexis Tsipras had urged his fellow members of parliament to vote 'yes' and survived despite up to 42 rebel votes or abstentions from his Syriza party's MPs, including a 'no' vote from former finance minister Yannis Varoufakis.
Analyze the relationship between 'Syriza' and 'Alexis Tsipras' within the context of the input sentence.
Options: publisher, business division, chairperson, chief executive officer