Explanations:The question asks for the old name of the present-day capital of Bihar, which is Patna. Patna has a rich and ancient history, and its historical name is Pataliputra. Pataliputra was a significant city in ancient India, particularly during the Maurya Empire, which was one of the largest empires in ancient India. The city was founded by Ajatashatru, the king of Magadha, around the 5th century BCE. It was a major center of learning and culture, and it is mentioned in various historical texts, including the works of Megasthenes, a Greek ambassador to the court of Chandragupta Maurya.
The name Pataliputra is derived from two Sanskrit words: "Patali," which refers to a type of creeper plant, and "putra," which means "son." According to legend, the city was named after the son of a Patali creeper. Over time, the city underwent several name changes and reconstructions, but Pataliputra remained its most prominent historical name until it was renamed Patna in the 16th century.
It is important to distinguish between the names of ancient cities and the names of empires or kingdoms. For example, Magadha was an ancient Indian kingdom that had Pataliputra as its capital. Licchavi refers to an ancient Indian republic, not a city name, and Prayag (now Allahabad) is a city in Uttar Pradesh, not in Bihar. Therefore, the correct answer to the question is Pataliputra, as it was the ancient name of the city that is now known as Patna, the capital of Bihar.