The correct answer is: All of the above.
Microliths are small, blade-like stone tools that were used by prehistoric peoples. They are typically made from flint or other hard stone, and they can be used for a variety of purposes, including hunting, woodworking, and hideworking.
The presence of microliths in Bihar suggests that prehistoric peoples in this region were adapted to hunting smaller animals, forest environments, and tool specialization. Microliths are well-suited for hunting smaller animals because they can be hafted onto arrows or spears, making them more effective at killing prey. They are also well-suited for use in forest environments because they are lightweight and easy to carry. Additionally, the fact that microliths are often found in association with other specialized tools suggests that prehistoric peoples in Bihar were skilled toolmakers who were able to produce a variety of tools for different purposes.
In conclusion, the presence of microliths in Bihar suggests that prehistoric peoples in this region were adapted to hunting smaller animals, forest environments, and tool specialization.