Final answer:
With respect to oxygen saturation, hemoglobin is fully saturated at the pO2 of the lungs due to higher oxygen levels facilitating binding, and partially saturated at the pO2 of the tissue as oxygen is released to meet the metabolic demands.
Step-by-step explanation:
The question pertains to the oxygen saturation level of hemoglobin in different physiological conditions. In the lungs, where the partial pressure of oxygen (pO2) is high, about 100 mm Hg, hemoglobin becomes fully saturated with oxygen. This is because the high pO2 facilitates the binding of oxygen to hemoglobin, forming oxyhemoglobin. When the oxygen-rich blood reaches tissues, the pO2 is lower; for example, it can be around 20 mm Hg in actively respiring muscle tissue. In this environment, hemoglobin releases oxygen, thus becoming partially saturated. Therefore, with respect to oxygen saturation, hemoglobin is fully saturated at the pO2 of the lungs and partially saturated at the pO2 of the tissue, making the correct answer (c) Fully; partially.