Select the false statement below about the structure of myoglobin.

a. the o2-binding pocket of myoglobin contains several nonpolar amino acid sidechains that can interact favorably with a nonpolar molecule of o2.

b. the polypeptide of myoglobin provides a pocket for o2 to fit, and stabilizes the bound o2 via hydrogen bonding with the distal his.

c. the polypeptide of myoglobin protects the heme iron from oxidation.

d. the active site of deoxy myoglobin is 5-coordinate with a histidine occupying one axial position while the other axial position is left open for oxygen binding.

e. myoglobin has a single polypeptide chain so it has 1o, 2o, 3o and 4o structure.