Which of These Statements Describes Haemoglobin

Multiple Choice

Which of these statements describes haemoglobin

A) It consists of a protein made up of four highly folded polypeptide chains and four iron-containing, non-protein, nitrogenous groups.
B) It appears reddish when combined with CO₂.
C) It can combine only with O₂ molecules.
D) It is found in the nuclei of red blood cells.