Which has a Score of 6 1, 3 0 ret.?
CREATE TABLE table_43443 (
    "Date" text,
    "Tournament" text,
    "Surface" text,
    "Opponent in the final" text,
    "Score" text
)
SELECT "Surface" FROM table_43443 WHERE "Score" = '6–1, 3–0 ret.'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Which has a Score of 6 1, 3 0 ret.? ### Input: CREATE TABLE table_43443 (
    "Date" text,
    "Tournament" text,
    "Surface" text,
    "Opponent in the final" text,
    "Score" text
) ### Response: SELECT "Surface" FROM table_43443 WHERE "Score" = '6–1, 3–0 ret.'