Carbon reduction method is employed for commercial extraction of:
This question has multiple correct options
$A.$ Haematite
$B.$ Cassiterite
$C.$ Iron pyrite
$D.$ Corundum

Hint: For answering this question we must remember the process of carbon reduction. Also, the knowledge of periodic tables is very important.

Complete step-by-step answer:
In carbon reduction metal ore is heated with carbon where carbon acts as a reduction agent that reduces metal oxides by removing oxygen in order to produce metal elements such as zinc, iron lead etc. and by obtaining oxygen, carbon itself gets oxidized, and gives carbon dioxide or carbon monoxide.
\[{\text{Metal oxide + Carbon}} \to {\text{Metal + CO/C}}{{\text{O}}_2}\]
But this approach works exceptionally i.e. only for less reactive metals i.e. elements in the reactivity sequence put below Aluminium e.g. iron, zinc, lead, copper etc. Since carbon cannot reduce more active metals such as sodium, it is used for such processes of extraction as electrolysis.

Now going through the extraction process of every oxide. We will observe that: -
Haematite is a process used for extraction of iron from $F{e_2}{O_3}$. In this carbon monoxide is used.
$F{e_2}{O_3} + 3CO \to 2Fe + 3C{O_2}$
Cassiterite is the process of extraction of tin from tin ore. So, we use Carbon reduction method for the extraction of Tin form Tin oxide i.e. $Sn{O_2}$
The process is $Sn{O_2}\; + \;2C \to Sn + 2CO$
In iron pyrite we cannot extract iron from the oxide because it is an exothermic reaction also there can be danger in mine. So, we do not iron extract from this. So, we use this in making sulphuric acid or jewellery making.
Corundum is the crystalline form of aluminium oxide i.e. $A{l_2}{O_3}$. In this aluminium is extracted using the process of electrolytic reduction.
Hence option B is the correct answer and as per this Carbon reduction method is employed for commercial extraction of Cassiterite.

Note: Carbon reduction process is used to remove metals from their oxide ores. The redox reaction mechanism is the fundamental chemistry behind this method of oxidizing one element and reducing the other.