The best answer is B.
An animal like the Llama lives in high altitudes from 7,400 to 12,800 meters above sea level.
When compared to other animals, Llamas have a lot more red blood cells per unit than other animals. More red blood cells mean more hemoglobin.
When hemoglobin combines with oxygen, oxyhemoglobin is formed. Thus oxyhemoglobin in Llamas is greatly increased than in most other animals and the Llamas are able to thrive in high altitude areas where oxygen is thinner.