Table:
text: 2007–08 West Ham United F.C. season
Pre-season
Pre-season
Match_ Date_ Competition_or_tour Ground Opponent Score1
1 14 Jul 2007 — A Dagenham & Redbridge 2 - 0
2 17 Jul 2007 — A Sigma Olomouc 0 - 1
3 21 Jul 2007 — A Lazio 0 - 2
4 24 Jul 2007 — A Leyton Orient 1 - 1
5 25 Jul 2007 — A MK Dons 2 - 3
6 28 Jul 2007 — A Southend United 3 - 1
7 31 Jul 2007 — A Norwich City 2 - 1
8 4 Aug 2007 — H Roma 2 - 1

Question: Which opponent in West Ham United FC pre-season 2007-08 has a date of 21 July 2007?