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:
| No. in series | No. in season | Title | Directedby | Writtenby | Originalairdate | Production code | U.S. viewers (million) |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 40.0 | 1.0 | "Out" | Paris Barclay | Kurt Sutter | September6,2011 | 4WAB01 | 4.93 |
| 41.0 | 2.0 | "Booster" | Guy Ferland | Dave Erickson & Chris Collins | September13,2011 | 4WAB02 | 3.71 |
| 42.0 | 3.0 | "Dorylus" | Peter Weller | Regina Corrado & Liz Sagal | September20,2011 | 4WAB03 | 3.42 |
| 43.0 | 4.0 | "Una Venta" | Billy Gierhart | Kurt Sutter & Marco Ramirez | September27,2011 | 4WAB04 | 3.28 |
| 44.0 | 5.0 | "Brick" | Paris Barclay | Dave Erickson & Brady Dahl | October4,2011 | 4WAB05 | 3.51 |
| 45.0 | 6.0 | "With an X" | Guy Ferland | Chris Collins & Regina Corrado | October11,2011 | 4WAB06 | 3.56 |
| 46.0 | 7.0 | "Fruit for the Crows" | Gwyneth Horder-Payton | Kurt Sutter & Liz Sagal | October18,2011 | 4WAB07 | 3.65 |
| 47.0 | 8.0 | "Family Recipe" | Paul Maibaum | Dave Erickson & Brady Dahl | October25,2011 | 4WAB08 | 3.82 |
| 48.0 | 9.0 | "Kiss" | Billy Geirhart | Regina Corrado & Marco Ramirez | November1,2011 | 4WAB09 | 3.63 |
| 49.0 | 10.0 | "Hands" | Peter Weller | Chris Collins & David Labrava & Kurt Sutter | November8,2011 | 4WAB10 | 3.93 |
| 50.0 | 11.0 | "Call of Duty" | Gwyneth Horder-Payton | Liz Sagal & Gladys Rodriguez | November15,2011 | 4WAB11 | 4.23 |
| 51.0 | 12.0 | "Burnt and Purged Away" | Paris Barclay | Kurt Sutter & Dave Erickson | November22,2011 | 4WAB12 | 3.85 |
| 52.0 | 13.0 | "To Be - Act 1" | Kurt Sutter | Kurt Sutter & Chris Collins | November29,2011 | 4WAB13 | 4.42 |
Question:
Who directed the episode with a production code of 4WAB04?
Answer:
Billy Gierhart