Livestock rearing in Assam is predominantly:

Small-scale and backyard farming
Intensive commercial farms
Organized dairy cooperatives
Nomadic pastoralism

The correct answer is (a) Small-scale and backyard farming.

Livestock rearing in Assam is predominantly small-scale and backyard farming. This is because the state has a large population of small farmers who rear livestock for their own consumption and for sale in local markets. The state also has a number of large commercial farms, but these are not as common as small-scale farms. Organized dairy cooperatives are also not as common in Assam as they are in some other states. Nomadic pastoralism is not practiced in Assam.

Here is a brief explanation of each option:

(a) Small-scale and backyard farming: This is the most common type of livestock rearing in Assam. Small farmers rear livestock such as cattle, buffalo, goats, and pigs for their own consumption and for sale in local markets. They often keep a few animals at home, and they may also have a small herd that they graze on common land.

(b) Intensive commercial farms: These are large farms that specialize in raising livestock for commercial purposes. They often have large herds of animals, and they use modern methods of livestock management. Intensive commercial farms are not as common in Assam as they are in some other states.

(c) Organized dairy cooperatives: These are cooperatives that are formed by dairy farmers. They work together to market their milk and to improve the quality of their livestock. Organized dairy cooperatives are not as common in Assam as they are in some other states.

(d) Nomadic pastoralism: This is a type of livestock rearing in which people move their herds from place to place in search of pasture. Nomadic pastoralism is not practiced in Assam.