The one that does not stabilize 2 and 3 structures of proteins is

Step 1: Identifying Protein Stabilizers — Secondary ($2^\circ$) and tertiary ($3^\circ$) structures of proteins are held together by various non-covalent and covalent interactions.

Step 2: Common Links — Primary among these are hydrogen bonds ($\alpha$-helices/$\beta$-sheets), disulfide linkages ($\ce{-S-S-}$), and hydrophobic van der Waals forces.

Step 3: Finding the Odd One — Peroxide linkages ($\ce{-O-O-}$) are not involved in biological protein stabilization. Thus, (c) is the correct choice.

Key Point: Disulfide bonds are critical for stabilizing the 3D folding (tertiary structure) of proteins like insulin.