CREATE TABLE table_71682 ("Date" CLOB, "Tournament" CLOB, "Surface" CLOB, "Opponent in the final" CLOB, "Score" CLOB)

What was the surface of the tournament where Anna Benzon was the opponent in the final?
SELECT "Surface" FROM table_71682 WHERE "Opponent in the final" = 'anna benzon'
SELECT "Surface" FROM "table_71682" WHERE "Opponent in the final" = 'anna benzon'