CREATE TABLE table_31721 ("Frequency" TEXT, "Call sign" TEXT, "Branding" TEXT, "Format" TEXT, "Owner" TEXT)

What is the branding frequency of cbc radio 2?
SELECT "Frequency" FROM table_31721 WHERE "Branding" = 'cbc radio 2'
SELECT "Frequency" FROM "table_31721" WHERE "Branding" = 'cbc radio 2'