How and why does the density of liquid water change on prolonged electrolysis?
(A) Decreases, as the proportion of \(\mathrm{H}_{2} \mathrm{O}\) increases
(B) Remains unchanged
(C) Increases, as the proportion of \(\mathrm{D}_{2} \mathrm{O}\) increases
(D) Increases, as the volume decreases