CREATE TABLE table_8768 ("Callsign" TEXT, "Frequency" TEXT, "Band" TEXT, "On-air ID" TEXT, "Purpose" TEXT)

What is the On-air ID of FM broadcaster 4nsa?
SELECT "On-air ID" FROM table_8768 WHERE "Band" = 'fm' AND "Callsign" = '4nsa'
SELECT "On-air ID" FROM "table_8768" WHERE "Band" = 'fm' AND "Callsign" = '4nsa'