CREATE TABLE table_64607 ("Rank" FLOAT, "Artist" CLOB, "Album" CLOB, "Peak position" CLOB, "Sales" FLOAT, "Certification" CLOB)

What was the album Closer: The Best of Sarah Mclachlan certified as?
SELECT "Certification" FROM table_64607 WHERE "Album" = 'closer: the best of sarah mclachlan'
SELECT "Certification" FROM "table_64607" WHERE "Album" = 'closer: the best of sarah mclachlan'