Match the list-I with list-II:
List-I (Class of Drug)                      List-II (Example)
(a) Antacid                                (i) Novestrol
(b) Artificial sweetener             (ii) Cimetidine
(c) Antifertility                        (iii) Valium
(d) Tranquilizers                      (iv) Alitame

We need to match each class of drug with its correct example.

An antacid is a substance that neutralises excess stomach acid. Cimetidine is a well-known antiulcer drug that acts as an H$$_2$$-receptor antagonist, reducing acid production in the stomach. So (a) matches with (ii).

An artificial sweetener is a synthetic substitute for sugar. Alitame is an artificial sweetener that is about 2000 times sweeter than sucrose. So (b) matches with (iv).

An antifertility drug is used for birth control. Novestrol (norethynodrel) is a synthetic progesterone derivative used as an oral contraceptive. So (c) matches with (i).

Tranquilizers are drugs used to reduce anxiety and tension. Valium (diazepam) is one of the most widely known tranquilizers. So (d) matches with (iii).

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