The correct option is (d).
Explanation
Harshavardhana belonged to the Pushyabhuti dynasty of Thanesar. His rise to power was precipitated by a political crisis involving the kingdoms of Thanesar, Kanauj, Malwa, and Gauda (Bengal) in the 7th century CE.Statement 1 is Incorrect: Harshavardhana was not the eldest son of Prabhakaravardhana. The eldest son was Rajyavardhana, who succeeded to the throne of Thanesar after their father’s death. Harshavardhana ascended the throne only after the untimely death of his elder brother, Rajyavardhana.
Statement 2 is Incorrect: Harshavardhana’s brother-in-law was Grahavarman, the Maukhari ruler of Kanauj. Grahavarman was killed by Devagupta, the ruler of Malwa, not by the ruler of Bengal. The ruler of Bengal (Gauda), Shashanka, was responsible for the treacherous killing of Harshavardhana’s elder brother, Rajyavardhana. Following these events, Harshavardhana united the kingdoms of Thanesar and Kanauj.
Key Takeaway: Harshavardhana succeeded his elder brother Rajyavardhana to the throne of Thanesar and later administered Kanauj after his brother-in-law, Grahavarman, was killed by the ruler of Malwa.