Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_8 (surface VARCHAR, opponent_s_ VARCHAR)
### Question:
Which Surface has an Opponent(s) of anna-lena grönefeld tatjana malek?
### Answer:
SELECT surface FROM table_name_8 WHERE opponent_s_ = "anna-lena grönefeld tatjana malek"