Which of the Following PL/SQL Blocks Requires the Variable to Always

Which of the following PL/SQL blocks requires the variable to always contain a particular value within the block?

A) DECLARE
Order NUMBER(2) := 0;
Departure DATE;
BEGIN
---- executable statements ---
END;
B) DECLARE
Order NUMBER(2,2) := .06;
Departure DATE;
BEGIN
---- executable statements ---
END;
C) DECLARE
Order CONSTANT NUMBER(2,2) := .02;
Departure DATE;
BEGIN
---- executable statements ---
END;
D) DECLARE
Order NUMBER(2) CONSTANT := .03;
Departure DATE;
BEGIN
---- executable statements ---
END;