已知下列数据:Cu<sup>+</sup>+e=Cu  φΘ=+0.522V;Cu<sup>2+</sup>+e=Cu<sup>+</sup>  φΘ=+0.167V确定<img src="https://nimg.ppkao.com/2019-05/caoguanchen/201905151705282447.png?sign=23b2f5909baae825cf7193b7f071b9d3&t=62d73105" />为()
A、+0.689V
B、-0.689V
C、-0.355V
D、+0.355V