Amid skyrocketing poverty and inflation, Argentinians face a stark choice on Sunday between two wildly different presidential candidates. Libertarian Javier Milei has led a disruptive campaign that has galvanised voters and won support from a faction of the traditional far-right. But a shock first-round victory for current Economy Minister Sergio Massa has set the scene for a down-to-the wire race in the final round of voting on Sunday.