In developing per-unit equivalent circuits for three-phase transformers, under balanced three-phase operation.

(i) A common \(\mathrm{S}_{\text {base }}\) is selected for both the \(\mathrm{H}\) and \(\mathrm{X}\) terminals.

(ii) The ratio of the voltage bases \(V_{\text {baseH }} / V_{\text {baseX }}\) is selected to be equal to the ratio of the rated line-to-line voltages \(\mathrm{V}_{\text {ratedHLL }} / \mathrm{V}_{\text {ratedXLL }}\).

(a) Only one of the above is true.

(b) Neither is true.

(c) Both statements are true.