Disulfide BondsA. Covalent interactions not found in all proteins. Peptide BondsB. Covalent interactions found in all proteins. Long-range interactionsC. Non-covalent interaction formed primarily on the interior of water-soluble proteins. Hydrophobic coreD. Covalent or non-covalent interactions formed b/w amino acid far from each other in primary structure.

Explanation:

A. Covalent interactions not found in all proteins - Disulfide Bonds

B. Covalent interactions found in all proteins - Peptide Bonds

C. Non-covalent interaction formed primarily on the interior of water-soluble proteins - Hydrophobic core

D. Covalent or non-covalent interactions formed b/w amino acid far from each other in primary structure - Long-range interactions.

Long-range interactions play an active role in the stability of protein molecules in terms of residue distances. disulfide bridges formed between thiol groups in two cysteine residues are an important component of the secondary and tertiary structure of proteins.

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be

i'm pretty sure it is letter c.) car