A healthy person living on the coast at sea level attempts to climb to a mountain peak at 14,000 feet, which of the following changes are expected? Group of answer choices Increased firing of the chemoreceptors. The alveoli PO2 decreases because of lower total O2 composition (< 21%) in air at high altitude. Decreased hematocrit levels due to chronic hypoxia. Increased respiratory rate Decreased respiratory rate A lower pulse oximeter reading because of a reduction in the arterial PO2. Decreased 2,3 BPG levels which will cause a rightward shift of oxygen-hemoglobin dissociation curve to facilitate O2 loading hemoglobin.