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:
| Club | Sport | Founded | League | Venue | Head Coach |
| --- | --- | --- | --- | --- | --- |
| Legia Warszawa (Polish) [ dead link ] | Football | 1916.0 | Ekstraklasa | Pepsi Arena | Jan Urban |
| Polonia Warszawa (Polish) | Football | 1911.0 | IV Liga | Stadion Polonii | Jacek Zieliński |
| Legia Warszawa | Basketball | 1947.0 | Second League | OSiR Bemowo | Wojciech Kiełbasiewicz |
| Polonia Gaz Ziemny Warszawa (Polish) | Basketball | 1911.0 | Polska Liga Koszykówki | Hala Sportowa "Koło" | Wojciech Kamiński |
| AZS Politechnika Warszawa | Volleyball | 1918.0 | Polska Liga Siatkówki | Hala UCSiR | Radosław Panas |
| Cumann Warszawa (Warsaw GAA ) | Gaelic Football and Hurling | 2009.0 | European Gaelic Football Championship | Stadion Skra , Pole Mokotowskie | Eoin Sheedy |
| Królewscy Warszawa | American Football | 2012.0 | Polska Liga Futbolu Amerykańskiego | Hutnik Stadium | James Deacon |
Question:
Sport of football, and a Venue of stadion polonii is what league?
Answer:
IV Liga