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 of opinion poll | Conductor | Sample size | For | Against | Undecided |
| --- | --- | --- | --- | --- | --- |
| 27 September 2009 | Sunday Independent/Quantum Research | 1000.0 | 68% | 17% | 15% |
| 26 September 2009 | Red C/Sunday Business Post | 1000.0 | 55% | 27% | 18% |
| 25 September 2009 | TNS/mrbi/Irish Times | 1000.0 | 48% | 33% | 19% |
| 18 September 2009 | Millward Brown/Lansdowne | 1000.0 | 53% | 26% | 21% |
| 12 September 2009 | Quantum Research/Sunday Independent | 1000.0 | 63% | 15% | 22% |
| 12 September 2009 | Red C/Post | 1000.0 | 52% | 25% | 23% |
| 4 September 2009 | TNS/mrbi | 1000.0 | 46% | 29% | 25% |
| 28 May 2009 | TNS/mrbi | 2000.0 | 54% | 28% | 18% |
| 13 May 2009 | TNS/mrbi | 2000.0 | 52% | 29% | 19% |
| 25 April 2009 | Quantum Research | 500.0 | 54% | 24% | 22% |
| 28 January 2009 | Red C/Post | 1001.0 | 58% | 28% | 14% |
| 23 January 2009 | Lansdowne | 1000.0 | 58% | 29% | 12% |
Question:
Who conducted the poll with sample size of 2000 that shows 18% undecided?
Answer:
TNS/mrbi