Scoping "Dynamic and Static" programming question with Ada

I am try to teach myself about some programming concepts relative to a class that I am taking.  I completed all the assignments in the chapter and then tried some of the more difficult exercises at the end of the book but I cannot seem to figure out the problem or answers to the below listed question, could someone please help.  An expalination of what the question is asking and the answer would be greatly appreciated.  Thanks Mark.

Consider the following Ada skeletal program:
1.  procedure Main is
2.         X : Integer;
3.         procedure Sub3; -- forward declaration of Sub3
4.                                     -- so it can be called by Sub1
5.         procedure Sub1 is
6.               X : Integer;
7.               procedure Sub2 is
8.               begin
9.       … -- in here, Sub3 is called
10.             end Sub2;
11.       begin – of  Sub1
12           … —in here, Sub2 is called
13.       end Sub1;
14.
15.       procedure Sub3 is
16.       begin
17.            …
18.       end Sub3;
19.
20.  begin – of Main
21.       … -- in here, Sub1 is called
22.  end Main

Assume that the execution of this program is in the following unit order:

Main calls Sub1
Sub1 calls Sub2
Sub2 calls Sub3

a. Assuming static scoping, which declaration of X is the correct one for a reference
    to X in the following:

i. Sub1
ii. Sub2
iii. Sub3

b. Repeat part a, but assume dynamic scoping.
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