ATHENS (Reuters) - Former Prime Minister Antonis Samaras announced he was stepping down as leader of Greece's conservative New Democracy opposition party after a strong vote for the 'No' position backed by the leftwing government in Sunday's referendum.
Take context from the input text and decide on the accurate relationship between 'New Democracy' and 'Antonis Samaras' from the options provided.
Options: chairperson, member of, industry, currency