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:
| Tie no | Home team | Score | Away team | Date |
| --- | --- | --- | --- | --- |
| 1 | West Bromwich Albion | 0–1 | Birmingham City | 18 February 1956 |
| 2 | Everton | 1–0 | Chelsea | 18 February 1956 |
| 3 | Doncaster Rovers | 0–2 | Tottenham Hotspur | 18 February 1956 |
| 4 | Sheffield United | 0–0 | Sunderland | 18 February 1956 |
| Replay | Sunderland | 1–0 | Sheffield United | 22 February 1956 |
| 5 | Newcastle United | 2–1 | Stoke City | 18 February 1956 |
| 6 | Manchester City | 0–0 | Liverpool | 18 February 1956 |
| Replay | Liverpool | 1–2 | Manchester City | 22 February 1956 |
| 7 | West Ham United | 0–0 | Blackburn Rovers | 18 February 1956 |
| Replay | Blackburn Rovers | 2–3 | West Ham United | 23 February 1956 |
| 8 | Charlton Athletic | 0–2 | Arsenal | 18 February 1956 |
Question:
What is Home Team, when Tie No is 4?
Answer:
Sheffield United