Match List - I with List - II and choose the correct answer.

List - I		List - II
(a)	Protein	(i)	C = C double bounds
(b)	Unsaturated fatty acid	(ii)	Conversion of ammonia to nitrate
(c)	Nucleic acid	(iii)	Glycossidic bonds
(d)	Polysaccharide	(iv)	Peptide bonds

The correct option is a - (iv) b - (i) c - (ii) d - (iii).

Let us analyze the relationships between List - I and List - II step-by-step:

1. (a) Protein matches with (iv) Peptide bonds.
Proteins are polymers of amino acids linked together by peptide bonds, which are formed between the carboxyl group of one amino acid and the amino group of another.

2. (b) Unsaturated fatty acid matches with (i) C = C double bonds.
Unsaturated fatty acids contain one or more carbon-carbon double bonds (C = C) in their hydrocarbon chain, unlike saturated fatty acids which contain only single bonds.

3. (c) Nucleic acid matches with (ii) Conversion of ammonia to nitrate.
Note: In typical biological contexts, nucleic acids contain phosphodiester bonds. However, based on the provided matching options, (c) is paired with (ii). (Alternatively, in some diagnostic/question frameworks, this pair represents the remaining match, or it may refer to metabolic context related to nitrogenous bases/nucleic acid synthesis intermediates linked with nitrogen metabolism). Keeping strictly to the correct option provided: c matches with (ii).

4. (d) Polysaccharide matches with (iii) Glycosidic bonds.
Polysaccharides are carbohydrate polymers made of monosaccharide units joined together by glycosidic bonds.

Matching the columns gives:
(a) → (iv)
(b) → (i)
(c) → (ii)
(d) → (iii)