NEET 2020 Chemistry question on Chemical Bonding

1. A.
   Blister copper has blistered appearance due to evolution of $\text{CO}_2$.
2. B.
   Vapour phase refining is carried out for Nickel by Van Arkel method.
3. C.
   Pig iron can be moulded into a variety of shapes.
4. D.
   Wrought iron is impure iron with 4% carbon.

[NEET 2020]