The correct answer is: a) Harshavardhana.
Bhaskaravarman was a prominent ruler of the Kamarupa Kingdom, known for his alliance with Harshavardhana. He was the son of Varmanaraja and succeeded his father to the throne in 600 CE. Bhaskaravarman was a powerful ruler and expanded the kingdom to its greatest extent. He was also a patron of the arts and literature.
Harshavardhana was a powerful ruler who ruled over the northern Indian subcontinent in the 7th century CE. He was the son of Prabhakaravardhana and succeeded his father to the throne in 606 CE. Harshavardhana was a great conqueror and expanded his kingdom to include much of northern India. He was also a patron of the arts and literature.
The two rulers were allies and fought together against the Chalukya dynasty. Bhaskaravarman was defeated by the Chalukyas in 620 CE and Harshavardhana died in 647 CE.
The other options are incorrect because:
- Samudragupta was a Gupta emperor who ruled in the 4th century CE. He was a powerful ruler who expanded the Gupta Empire to its greatest extent.
- Chandragupta Maurya was the founder of the Mauryan Empire in the 4th century BCE. He was a powerful ruler who united much of the Indian subcontinent under his rule.
- Pulakeshin II was a Chalukya emperor who ruled in the 7th century CE. He was a powerful ruler who expanded the Chalukya Empire to its greatest extent.