The metals below, together with the compounds found in their ores, are listed. metal: Al, Ca, Pb, Na, Fe, Mg compound present in ore: $\text{Al}_2\text{O}_3$, $\text{CaCO}_3$, $\text{PbS}$, $\text{NaCl}$, $\text{Fe}_2\text{O}_3$, $\text{MgCO}_3$ What kind of reaction occurs when each of these metals is extracted from its ore?
- Adecomposition by heat
- Belectrolysis
- Cprecipitation
- Dreduction