单选题 The construct
cobegin
Statement1;
Statement2;
coend
means Statement1 and Statement2 are to be executed in parallel. The only two atomic actions in this construct are loading the value of a variable and storing into a variable. For the program segment
x:=0;
y:=0;
cobegin
begin
x:=1,
y:=y+x;
end;
begin
y:=2;
x:=x+3;
end
coend
Which of the following indicate(s) possible values for the variables when the segment finishes execution?
Ⅰ. x=1, y=2
Ⅱ. x=1, y=3
Ⅲ. x=4, y=6