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
A．Ⅰ
B．Ⅱ and Ⅲ
C．Ⅰ and Ⅲ
D．Ⅱ and Ⅲ