Correct Option: C

Harsha's ambition of extending his power to the Deccan and Southern India were stopped by the great Chalukya Emperor of South India Pulakeshini-II, the Chalukya king of Vatapi in Northern Karnataka along the banks of river Narmada. Pulakeshi defeated Harsha's army on the banks of the river Narmada in 620. A truce was agreed upon and the river Narmada was marked as the southern boundary of Harsha's kingdom.