user: Question: Name the Nationality / Opponent of Rosario?
Columns: ['Date', 'Nationality / Opponent', 'Ground', 'Result', 'Competition']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['21 October 1989', 'New Zealand', 'Saint Helens Cricket and Football Ground, Swansea', '22-37', 'New Zealand Tour of Great Britain and Ireland 1989']
SQL:

assistant: SELECT "Competition" FROM "Table" WHERE "Nationality / Opponent" = 'Rosario';