Which of the following statements is correct?
A. Hemoglobin binds O2 cooperatively, while myoglobin does not.
B. Myoglobin binds O2 cooperatively, while hemoglobin does not.
C. Myoglobin binds O2 more weakly than hemoglobin.
D. The O2 binding curve (fractional saturation vs. pO2) for myoglobin is sigmoidal, while that of hemoglobin is hyperbolic.
E. both B and D