Option b is the correct answer. Pulakeshin-II was the most famous ruler of the Chalukya dynasty of Vatapi (modern Badami) in Karnataka. He ruled from 610 CE to 642 CE and expanded his empire by conquering many regions of South and Central India. He also successfully resisted the invasion of Harsha, who had crossed the Narmada River in 620 CE with a large army. Pulakeshin-II met Harsha on the banks of the Narmada and fought a fierce battle, which resulted in a stalemate. Harsha was forced to retreat and acknowledge the sovereignty of Pulakeshin-II over the Deccan and South India. This event is recorded in the Aihole inscription.