$4.$ In the following code, identify $($circle or highlight$)$ examples of these procedural constructs: variable, conditional control statement, reusable$/$callable program unit, and an assignment statement.

DECLARE

v$\_$first$\_$name varchar$2(40)$; v$\_$last$\_$name varchar$2(40)$; v$\_$first$\_$letter varchar$2(1)$;

BEGIN

SELECT first$\_$name, last$\_$name INTO v$\_$first$\_$name, v$\_$last$\_$name FROM students

WHERE student$\_$id $=105$; v$\_$first$\_$letter :$=$ get$\_$first$\_$letter$($v$\_$last$\_$name$)$; IF $\text{'}$N$\text{'}>\text{'}$v$\_$first$\_$letter' THEN

DBMS$\_$OUTPUT.PUT$\_$LINE$(\text{'}$The last name for $\text{'}||$ v$\_$first$\_$name $||\text{'}\text{'}||$ v$\_$last$\_$name $||\text{'}$ is between A and M$\text{'})$;

ELSE

DBMS$\_$OUTPUT.PUT$\_$LINE$(\text{'}$The last name for $\text{'}||$ v$\_$first$\_$name $||\text{'}\text{'}||$ v$\_$last$\_$name $||\text{'}$ is between N and Z$\text{'})$;

END IF; END;