Match List-I with List-II:
List-I (process)                                         List-II (catalyst)
(a) Deacon's process                               (i) ZSM-5
(b) Contact process                                (ii) CuCl$$_2$$
(c) Cracking of hydrocarbons                  (iii) Ni
(d) Hydrogenation of vegetable oils        (iv) V$$_2$$O$$_5$$
Choose the most appropriate answer from the options given below:

We need to match each industrial process with the catalyst used in it.

Deacon's process is used to manufacture chlorine gas from HCl by oxidation: $$4\text{HCl} + \text{O}_2 \xrightarrow{\text{CuCl}_2} 2\text{Cl}_2 + 2\text{H}_2\text{O}$$. The catalyst employed is $$\text{CuCl}_2$$ (cupric chloride), so (a) matches with (ii).

The Contact process is used for manufacturing sulphuric acid. In this process, $$\text{SO}_2$$ is oxidized to $$\text{SO}_3$$ using $$\text{V}_2\text{O}_5$$ (vanadium pentoxide) as the catalyst, so (b) matches with (iv).

Cracking of hydrocarbons in the petroleum industry is carried out using zeolite catalysts. ZSM-5 is a well-known zeolite catalyst used for this purpose, so (c) matches with (i).

Hydrogenation of vegetable oils (conversion of unsaturated fats to saturated fats, as in the manufacture of vanaspati ghee) uses finely divided nickel ($$\text{Ni}$$) as the catalyst, so (d) matches with (iii).

Therefore the correct matching is: a-ii, b-iv, c-i, d-iii, which corresponds to Option A.