In metallurgy,calcination is used for .........

The chemical reaction that involves the roasting process is:

$A$ metal obtained directly by roasting of its sulphide ore is

Given below are two statements:
Statement-$I$ : In the metallurgy process,sulphide ore is converted to oxide before reduction.
Statement-$II$ : Oxide ores in general are easier to reduce.
In the light of the above statements,choose the most appropriate answer from the options given below :

Which of the following is an example of the calcination process?

Explain the isolation of metals from concentrated ore.