what is the surface when the opponent is selma babic?
CREATE TABLE table_name_31 (surface VARCHAR, opponent VARCHAR)
SELECT surface FROM table_name_31 WHERE opponent = "selma babic"
### Context: CREATE TABLE table_name_31 (surface VARCHAR, opponent VARCHAR) ### Question: what is the surface when the opponent is selma babic? ### Answer: SELECT surface FROM table_name_31 WHERE opponent = "selma babic"