Users in which country has posted more numbers of positive tweets, Argentina or Australia?
"Argentina" and "Australia" are both Country; positive tweets refers to Sentiment > 0; Country posted more number of tweets refers to Country where Max(Count(TweetID))
SELECT T2.Country FROM twitter AS T1 INNER JOIN location AS T2 ON T2.LocationID = T1.LocationID WHERE T2.Country IN ('Argentina', 'Australia') AND T1.Sentiment > 0 GROUP BY T2.Country ORDER BY COUNT(T1.TweetID) DESC LIMIT 1