Roasting results in the formation of oxides. But why are oxide ores are subjected to roasting?

To get crude metal with using oxidizing agent

To remove volatile impurities in the form of their oxides

Roasting results in the formation of oxides. But why are oxide ores ar

1.	Roasting results in the formation of oxides. But why are oxide ores are subjected to roasting?
A.	To avoid gangue particles
B.	To get crude metal with using oxidizing agent
C.	To remove volatile impurities in the form of their oxides
D.	To make the ore porous
Answer» D. To make the ore porous