Which declaration is correct for a stored program unit?

Question $1$ options:

CREATE OR REPLACE FUNCTION tax$\_$amt $($p$\_$id NUMBER$)$ RETURN NUMBER$(10,2)$

CREATE OR REPLACE FUNCTION tax$\_$amt $($p$\_$id NUMBER$)$ RETURN NUMBER

CREATE OR REPLACE PROCEDURE tax$\_$amt $($p$\_$id NUMBER, p$\_$amount OUT NUMBER$(10,2))$

CREATE OR REPLACE PROCEDURE tax$\_$amt $($p$\_$id NUMBER$)$ RETURN NUMBER