Option b is the correct answer. The Maukhari dynasty was a post-Gupta dynasty that controlled the vast plains of Ganga-Yamuna for over six generations from their capital at Kannauj. Kannauj was a prosperous and cosmopolitan city that later became the capital of Harsha, the ruler of the Pushyabhuti dynasty. The Maukhari capital is mentioned in several sources, such as their inscriptions, their coins, the Harshacharita, and the Aryamanjushrimulakalpa.