Based on the Plot of Oxygen Saturation Versus Partial Pressure

Multiple Choice

Based on the plot of oxygen saturation versus partial pressure of oxygen, which of the following statements is true?

A) at oxygen pressure >100 mm Hg, hemoglobin dissociates into individual subunits so that it is able to bind oxygen similar to myoglobin
B) at typical resting capillary oxygen pressure of ~30 mm Hg, hemoglobin has only 1 of its 4 oxygen binding sites filled while myoglobin is nearly saturated with oxygen
C) under periods of extreme muscle exertion, capillary oxygen pressure can drop to 10 mm Hg, allowing release of ~90% of oxygen carried by hemoglobin
D) the structure of hemoglobin allows for complete release of oxygen in capillary beds at all times
E) none of the above