The correct option is Sannati in Gulbarga district.
Explanation
The site of Sannati (specifically the Kanaganahalli excavation) represents a major Buddhist centre in South India. It is located on the banks of the Bhima River in the Kalaburagi (formerly Gulbarga) district of Karnataka.
Detailed Analysis:
- Sannati (Kanaganahalli): This site houses the largest excavated stupa in Karnataka, referred to in inscriptions as the Adholoka Maha Chaitya. The stupa dates back to the Mauryan period and saw significant expansion during the Satavahana rule. A landmark discovery at this site was a limestone relief panel depicting Emperor Ashoka with his queens, inscribed with the title "Raya Asoko". This is the only known inscribed image of the Mauryan Emperor.
- Aihole and Badami: Located in the Bagalkot district, these sites are associated with the Chalukya dynasty. They are renowned for rock-cut caves and structural temples dedicated to Hindu and Jain traditions, marking the evolution of the Vesara style of temple architecture. They are not characterized by large Buddhist stupas.
- Hampi: Located in the Bellary (Ballari) district, Hampi was the capital of the Vijayanagara Empire. It is famous for its grand Hindu temples, royal complexes, and stone chariots, rather than Buddhist stupa architecture.
Key Takeaway: Sannati is the most significant Buddhist site in Karnataka, featuring a massive Maha Stupa and the only surviving inscribed portrait of Emperor Ashoka.