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

List - I	List - II
(a) Protein	(i) C = C double bonds
(b) Unsaturated fatty acid	(ii) Phosphodiester bonds
(c) Nucleic acid	(iii) Glycosidic bonds
(d) Polysaccharide	(iv) Peptide bonds

To find the correct match between List - I (biomolecules) and List - II (associated chemical bonds or features), we analyze each pair step-by-step:

(a) Proteins: Proteins are polymers of amino acids. Amino acids are linked together by peptide bonds, which are covalent bonds formed between the carboxyl group of one amino acid and the amino group of the next.
Hence, (a) matches with (iv).

(b) Unsaturated fatty acids: Fatty acids consist of a carboxylic acid with an aliphatic chain. Unsaturated fatty acids contain one or more C = C double bonds within their hydrocarbon chain, unlike saturated fatty acids which contain only single bonds.
Hence, (b) matches with (i).

(c) Nucleic acids: Nucleic acids (like DNA and RNA) are polymers of nucleotides. The nucleotides are joined together by phosphodiester bonds, which link the 3' carbon atom of one sugar molecule to the 5' carbon atom of another.
Hence, (c) matches with (ii).

(d) Polysaccharides: Polysaccharides are complex carbohydrates made of monosaccharide units. These monosaccharide units are linked together by covalent bonds known as glycosidic bonds.
Hence, (d) matches with (iii).

Combining all the correct matches:
a - (iv), b - (i), c - (ii), d - (iii)