Answer:
C) It likely has extensive quaternary structure to maintain its globular shape
Step-by-step explanation:
Quaternary structure exists for proteins that have more than on polypeptide chain such as hemoglobin (four polypeptide chain).
The protein in the statement has one polypeptide chain that why it cannot have extensive quaternary structure to maintain its globular shape.
Interactions like hydrogen bonding and london dispersion forces hold the subunits together in quaternary structure.