The correct answer is: a) Hunter-gatherer communities.
The hilly regions of Assam in prehistoric times were likely inhabited by hunter-gatherer communities. This is because the hilly regions of Assam are not suitable for large-scale agriculture, and hunter-gatherer communities are able to survive in a variety of environments.
Early agricultural settlers would have needed to find land that was suitable for farming, and the hilly regions of Assam are not ideal for this. Large urban civilizations would also have needed to find land that was suitable for farming, and the hilly regions of Assam are not ideal for this. Pastoralist groups would have needed to find land that was suitable for grazing their animals, and the hilly regions of Assam are not ideal for this.
Therefore, the most likely answer is that the hilly regions of Assam in prehistoric times were inhabited by hunter-gatherer communities.
Here is a brief explanation of each option:
- Option a: Hunter-gatherer communities are groups of people who live by hunting animals and gathering wild plants. They are able to survive in a variety of environments, including hilly regions.
- Option b: Early agricultural settlers are groups of people who began to farm in the early stages of human history. They needed to find land that was suitable for farming, which the hilly regions of Assam are not.
- Option c: Large urban civilizations are large cities with complex societies. They needed to find land that was suitable for farming, which the hilly regions of Assam are not.
- Option d: Pastoralist groups are groups of people who raise livestock. They need to find land that is suitable for grazing their animals, which the hilly regions of Assam are not.