The correct option is B Magadha
In northern India in 6th century BC Magadha emerged as the most powerful state. Magadha was an ancient Indian kingdom in southern Bihar, and was counted as one of the sixteen Mahajanapadas, 'Great Countries' of ancient India. Magadha played an important role in the development of Jainism and Buddhism, and two of India's greatest empires, the Maurya Empire and Gupta Empire.