What causes the red blood cell count in humans to rise when they begin living at high altitude?
- Ato allow more carbon dioxide to be excreted by the lungs, preventing a fall in blood pH
- Bto allow more oxygen to be taken up by the haemoglobin as the partial pressure of oxygen is lower
- Cto allow more oxygen to be taken up by the lungs as there is a lower percentage of oxygen in the air
- Dto allow more oxygen to be transported as the affinity of haemoglobin for oxygen is lowered