Which of the following is a mineral of sulfur?

Make the correct pairs from below mentioned $X$ and $Y$:

$X$	$Y$
$1$. Extraction of sulphur	$p$. Contact process
$2$. Production of nitric acid	$q$. Frasch method
$3$. Production of sulphuric acid	$r$. Haber's process
$4$. Production of ammonia gas	$s$. Ostwald's method

$(a)$ What type of ores are calcined? Illustrate by giving a suitable example.
$(b)$ In what form is the calcined ore obtained,and how can it be reduced? Give chemical equations of the reduction process involved for the example provided by you.
$(c)$ Name two metals used as reducing agents by displacing metals of lower reactivity from their compounds.

Which of the following methods is $NOT$ a method for the refining of metals?

Which of the following ores is in the form of sulphide?

Which method is used for the refining of metals having low melting points?