[supriyo banerjee]

But we cant say either the amino acid residue made up of by cystine or not...if it is thn your answer is no doubtly ture bcz we knw disulfide bond is covalent bond which is more stable...but disulfide bond in protein is very rare nd its unstable in cytosol for that reason methonine couldnt form the disulfide bridge and only stabilized by hydrogen bonding...if we see the ratio of the protein stability...most of the protein stable by the hydrogen bond or hydrophobic interaction...in salt bridge there are two types of effect are present one electrostatic interaction and one is hydrogen bonding which rise the stability of super impose molecular structure...so i think T consits a super impose molecular structure...for tht reason option D..