The correct answer is: b) Mithun and yaks.
Free-range grazing is a common practice for livestock rearing in Arunachal Pradesh, particularly for mithun and yaks. Mithun are a type of cattle that are native to the region, while yaks are a type of wild ox. Both animals are well-adapted to the harsh climate and terrain of Arunachal Pradesh, and they can thrive on the sparse vegetation that is available.
Cattle and buffaloes are also raised in Arunachal Pradesh, but they are not as well-adapted to the climate and terrain as mithun and yaks. As a result, they are typically kept in enclosed areas and fed on cultivated fodder.
Sheep and goats are also raised in Arunachal Pradesh, but they are not as common as cattle, buffaloes, mithun, and yaks. This is because they are not as well-adapted to the climate and terrain of the region.
Pigs and poultry are not commonly raised in Arunachal Pradesh. This is because they are not as well-adapted to the climate and terrain of the region. Additionally, there is a cultural taboo against eating pork in many parts of Arunachal Pradesh.