Hint: Bimbisara was a king who ruled The Kingdom of Magadha during the time of Gautama Buddha of the Buddha tradition and Vardhamana Mahavira of the Jains. Bimbisara followed early Buddhist and Jain beliefs and endorsed both these religions equally. He ruled different regions during his reign other than Magadha. This includes a place called Girivraja which is identified as Rajgiriha in the state of Bihar today which was built by Bimbisara himself.
Complete step by step answer:
Bimbisara became the king of the Magadha Kingdom in 400\ BC. He was the son of a small king known by the name Bhattiya and belonged to the Haryanka dynasty. The Haryanka dynasty is believed to be one of the prominent rulers of Magadha. Bimbisara is the first king whose reign is marked historically with well-developed proofs; the accounts for kings before him are incomplete or mythical to some extent. Even though Bimbisara had a small defense structure to accompany him, he was able to establish one of the effective structures for administration and government. He also developed a well-defined tax system as 80,000 villages were under his rule. Each village had a headman in charge and high-ranking officials were appointed to take charge of judicial, military, and financial administration. Any officials who underperformed were replaced and he listened to the advice of his closest high-ranking ministers. The Mahajanapadas and the Janapadas were the major political groups at the time. During the earlier days of the Haryanka Dynasty, the Indian civilization was being distributed over different zones from the northwest to the eastern and central parts of India. These zones were ruled by four great kingdoms. They were Kosala, Avanti, Vatsa, and Magadha.
So, the correct answer is Option B.
Note: The kingdom of Avanti was roughly present-day central India, mainly the state of Madhya Pradesh. Vatsa was a part of present-day Uttar Pradesh state, while the ancient Magadha Empire corresponds roughly to the present-day state of Bihar, Jharkhand, some parts of West Bengal, Odisha, Uttar Pradesh, and terrains of Nepal and Bangladesh. This makes Magadha the biggest empire of the time. Bimbisara was later imprisoned by his son Ajatashatru in order to take over the throne of the kingdom of Magadha. Ajatashatru later ordered his father's release after the birth of his first child, but by then it was too late and Bimbisara had already died. This was reported to have taken place around 492 BC.