Consider two chemical reactions (A) and (B) that take place during metallurgical process:
(A) ZnCO$$_{3(s)} \xrightarrow{\Delta}$$ ZnO$$_{(s)}$$ + CO$$_{2(g)}$$
(B) 2ZnS$$_{(s)}$$ + 3O$$_{2(g)} \xrightarrow{\Delta}$$ 2ZnO$$_{(s)}$$ + 2SO$$_{2(g)}$$
The correct option of names given to them respectively is:

In metallurgy, two important thermal processes are calcination and roasting, which differ based on the ore type and conditions used.

Reaction (A): $$\text{ZnCO}_{3(s)} \xrightarrow{\Delta} \text{ZnO}_{(s)} + \text{CO}_{2(g)}$$

This is calcination — the process of heating a carbonate ore in the absence of air (or limited air) to decompose it into the metal oxide and carbon dioxide. Carbonate ores are typically subjected to calcination.

Reaction (B): $$2\text{ZnS}_{(s)} + 3\text{O}_{2(g)} \xrightarrow{\Delta} 2\text{ZnO}_{(s)} + 2\text{SO}_{2(g)}$$

This is roasting — the process of heating a sulphide ore in excess of air (in the presence of oxygen) to convert it into the metal oxide, with the release of sulphur dioxide gas. Sulphide ores are treated by roasting.

The key distinction is that calcination involves carbonate (or hydrated) ores heated in limited/no air, while roasting involves sulphide ores heated in excess air. Therefore, (A) is calcination and (B) is roasting.