user: Question: What kind of surface was the Tournament at Sunderland played on?
Columns: ['Outcome', 'Date', 'Tournament', 'Surface', 'Opponent', 'Score']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Winner', '6 November 2005', 'Pune', 'Hard', 'Isha Lakhani', '6-4 6-1']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Tournament" = 'Sunderland';