当$$x,  y$$满足条件$$\left\textbar{} x \right\textbar+\left\textbar{} y \right\textbar\leqslant 1$$时，变量$$z=x-y+2$$的取值范围是．
选项为:A:$$\left[ \frac{\sqrt{2}}{2},\frac{3\sqrt{2}}{2} \right]$$  B:$$\left( 1,  3 \right)$$  C:$$\left[ 1,  3 \right]$$  D:$$\left( \frac{\sqrt{2}}{2},\frac{3\sqrt{2}}{2} \right)$$  请回答其中一个选项.