The diagram illustrates a circuit set up to electrolyse aqueous copper(II) sulfate. Which arrows show how the copper ions move in the electrolyte and how the electrons move in the external circuit?
- Acopper ions: 1, electrons: 3
- Bcopper ions: 1, electrons: 4
- Ccopper ions: 2, electrons: 3
- Dcopper ions: 2, electrons: 4