Given the following Ada program: For each of the four marked points, list each visible variable if the static scoping is used. Show the stack with all activation record instances, including static and dynamic chains, when execution reaches point 2. What are the purposes of using static and dynamic links in activation records? procedure Main is X, Y: Integer; procedure Sub1 is Y, Z: Integer begin -- of Sub1 point 1 Sub2; end; -- of Sub1 procedure Sub2 is W: Integer; procedure Sub3(B: Integer) is A: Integer begin -- of Sub3 point 2 end; -- of Sub3 begin -- of Sub2 point 3 end; -- of Sub2 begin -- of Main point 4 Sub1; end; -- of Main