Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Date | Nationality / Opponent | Ground | Result | Competition |
| --- | --- | --- | --- | --- |
| 21 October 1989 | New Zealand | Saint Helens Cricket and Football Ground, Swansea | 22-37 | New Zealand Tour of Great Britain and Ireland 1989 |
| 5 November 1994 | South Africa | Saint Helens Cricket and Football Ground, Swansea | 7-78 | South Africa Tour of Europe 1994 |
| 10 January 1998 | Rosario | Saint Helens Cricket and Football Ground, Swansea | 51-31 | Welsh Rugby Union Challenge Trophy |
| 14 January 1998 | Northern Bulls | Saint Helens Cricket and Football Ground, Swansea | 34-34 | Welsh Rugby Union Challenge Trophy |
| 18 January 1998 | Canada XV | Saint Helens Cricket and Football Ground, Swansea | 38-29 | Welsh Rugby Union Challenge Trophy |
Question:
Name the Nationality / Opponent of rosario?
Answer:
Welsh Rugby Union Challenge Trophy