The compound(s) that is(are) removed as slag during the extraction of copper is:
I. \( \mathrm{CaO} \) II. \( \mathrm{FeO} \) III. \( \mathrm{Al_2O_3} \) IV. \( \mathrm{ZnO} \) V. \( \mathrm{NiO} \)
Choose the correct answer from the option given below:
