The correct answer is: All of the above.
The prehistoric cultures of Bihar show influences from regions in Northern India, Nepal, and Eastern India. This is evident in the archaeological remains found in the region, which show similarities to cultures in these other regions. For example, the pottery found in Bihar is similar to pottery found in Northern India, and the stone tools found in Bihar are similar to stone tools found in Nepal. This suggests that there was contact between the people of Bihar and the people of these other regions.
The prehistoric cultures of Bihar are also similar to the cultures of other parts of India. For example, the people of Bihar practiced agriculture, and they built temples and other religious structures. This suggests that the people of Bihar were part of a larger Indian culture.
The prehistoric cultures of Bihar are an important part of the history of India. They provide us with insights into the early development of Indian culture.