(N/A) Glycosidic bond: This bond is formed between two carbon atoms,typically $C-1$ and $C-4,$ of adjacent monosaccharide units through a dehydration reaction.
$(b)$ Peptide bond: This is a covalent bond formed between the carboxyl group $(-COOH)$ of one amino acid and the amino group $(-NH_2)$ of the next amino acid,resulting in a $-NH-CO-$ linkage.
$(c)$ Phosphodiester bond: This is a strong covalent bond that connects the $3'$ carbon atom of one sugar molecule to the $5'$ carbon atom of another sugar molecule via a phosphate group. These bonds form the sugar-phosphate backbone of nucleic acids like $DNA$ and $RNA$.