increased digestion rate growth of additional teeth reduction of respiration rate production of more red blood cells
I gave my students this multiple choice question: Biologists moved a predator from sea level to a higher altitude, where they noticed that the predator became tired more quickly. If this predator had to live at a higher altitude, which adaptation would be necessary for it to survive?

Only one answer is correct among these 4 choices:
- increased digestion rate
- growth of additional teeth
- reduction of respiration rate
- production of more red blood cells

Could you tell me which one is correct?

production of more red blood cells