user: Question: On which Surface will Estrella Cabeza Candela play?
Columns: ['Date', 'Tournament', 'Surface', 'Opponent', 'Score']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['August 6, 2006', 'Bad Saulgau , Germany', 'Clay', 'Josipa Bek', '6–1, 6–0']
SQL:

assistant: SELECT "Surface" FROM "Table" WHERE "Opponent" = 'Estrella Cabeza Candela';