12. Which of the following is not correct concerning the oxygenation plot of proteins X and Y shown below? (A) Protein X exhibits tighter oxygen binding than protein Y. (B) Protein Y would function as a better transport protein than protein X. (C) Protein X exhibits cooperative binding, whereas Y does not. (D) Protein X corresponds to myoglobin, and protein Y corresponds to hemoglobin. (E) Protein Y contains multiple binding sites.