CREATE TABLE table_name_32 (image_quality VARCHAR(255), date VARCHAR(255), multiple_sessions VARCHAR(255), authentication VARCHAR(255))
what is the image quality when the multiple sessions is x, the authentication is ✓ and the date is may 15, 2007?
    
SQL: SELECT image_quality FROM table_name_32 WHERE multiple_sessions = "x" AND authentication = "✓" AND date = "may 15, 2007"