下列原电池中，电动势最大的是A()Zn|Zn+(c)‖Cu+(c)|Cu(+)B()Zn|Zn+(.c)‖Cu+(.c)|Cu(+)C()Zn|Zn+(c)‖Cu+(.c)|Cu(+)D()Zn|Zn+(.c)‖Cu+(c)|Cu(+)E()Zn|Zn+(c)‖Cu+(c)|Cu(+)