Identify each test and its characteristic observation

We match the tests in List I with the observations in List II.

A. $\mathrm{Br_2}$ water test

Bromine water is decolourised by unsaturation or certain activated compounds.

So, the observation is:

$\text{Reddish orange colour disappears}$

Hence,

$A \to II$

B. Ceric ammonium nitrate test

Ceric ammonium nitrate test is used for alcohols. Alcohols give a red colour with ceric ammonium nitrate.

Hence,

$B \to III$

C. Ferric chloride test

Ferric chloride gives coloured complexes with phenols, producing colours like blue, green, violet, or red.

Hence,

$C \to IV$

D. 2,4-DNP test

$2,4$-dinitrophenylhydrazine reacts with aldehydes and ketones to form a yellow-orange or orange-red precipitate.

Hence,

$D \to I$

Final matching

Therefore, the correct matching is:

$A-II,\; B-III,\; C-IV,\; D-I$

Compare with options

This corresponds to Option A.

Comparison with stored correct answer

Stored correct answer = A

Derived answer = A

So, they agree.