The correct answer is: a) Yaks.
Yaks are a type of cattle that are well-adapted to living in high altitudes. They have thick fur that helps to keep them warm, and they have large lungs that allow them to breathe in the thin air. Yaks are also very hardy animals, and they can survive on a diet of grass and other plants that are found in high-altitude areas.
Goats are another type of animal that is well-suited to living in high altitudes. They are also hardy animals, and they can survive on a diet of grass and other plants. However, goats do not have the same thick fur as yaks, so they are not as well-protected from the cold.
Poultry, such as chickens and ducks, are not well-suited to living in high altitudes. They are not as hardy as yaks or goats, and they are more susceptible to the cold. Additionally, poultry require a lot of food, which can be difficult to find in high-altitude areas.
Pigs are also not well-suited to living in high altitudes. They are not as hardy as yaks or goats, and they are more susceptible to the cold. Additionally, pigs require a lot of food and water, which can be difficult to find in high-altitude areas.