Correct Option: C

Globular proteins have no systematic structures. There may be single chains, two or more chains which interact in the usual ways or there may be portions of the chains with helical structures, pleated structures, or completely random structures. Common globular proteins include egg albumin, hemoglobin, myoglobin, insulin, serum globulins in blood, and many enzymes. Water-soluble globular proteins have hydrophobic amino acids present in the interior of the protein structure forming hydrophobic bonds. So, valine is the amino acid residue most likely to be present on the interior.