CREATE TABLE table_40539 ("Date" CLOB, "Cover model" CLOB, "Centerfold model" CLOB, "Interview subject" CLOB, "20 Questions" CLOB)

Which Cover model has a Centerfold model of scarlett keegan?
SELECT "Cover model" FROM table_40539 WHERE "Centerfold model" = 'scarlett keegan'
SELECT "Cover model" FROM "table_40539" WHERE "Centerfold model" = 'scarlett keegan'