CREATE TABLE table_27744 ("Rd." TEXT, "Event" TEXT, "Circuit" TEXT, "City / State" TEXT, "Date" TEXT, "Championship" TEXT, "Challenge" TEXT, "Production" TEXT)

Who made the challenge in the Australian Grand Prix?
SELECT "Challenge" FROM table_27744 WHERE "Event" = 'Australian Grand Prix'
SELECT "Challenge" FROM "table_27744" WHERE "Event" = 'Australian Grand Prix'