The correct answer is option 'D', the temples of Jagannath at Puri and the Sun-temple at Konark were constructed during the reign of the Choda Ganga dynasty in Orissa.

During the Choda Ganga dynasty, which ruled Orissa from the 11th to the 14th century, several remarkable architectural and cultural developments took place. The construction of the temples of Jagannath at Puri and the Sun-temple at Konark are considered to be the most notable achievements of this dynasty.

1. Choda Ganga dynasty in Orissa:
The Choda Ganga dynasty was established by King Anantavarman Chodaganga Deva in the 11th century. This dynasty played a significant role in shaping the cultural and architectural landscape of Orissa.

2. The temple of Jagannath at Puri:
The temple of Jagannath at Puri is one of the most famous Hindu pilgrimage sites in India. It is dedicated to Lord Jagannath, an incarnation of Lord Vishnu. The construction of this temple was initiated by King Anantavarman Chodaganga Deva and was completed by his descendant, King Ananga Bhima Deva III. The temple is renowned for its exquisite architecture, intricate carvings, and the annual Rath Yatra festival.

3. The Sun-temple at Konark:
The Sun-temple at Konark is another architectural marvel built during the Choda Ganga dynasty. It is dedicated to the Sun god, Surya. The construction of this temple was commissioned by King Narasimhadeva I and was completed around the 13th century. The temple is famous for its colossal chariot-like structure, adorned with intricate stone carvings depicting various mythological scenes.

4. Architectural style:
Both the temples of Jagannath at Puri and the Sun-temple at Konark exhibit the Kalinga style of architecture, characterized by elaborate carvings, towering structures, and intricate detailing. These temples are excellent examples of the architectural brilliance and craftsmanship of the Choda Ganga dynasty.

In conclusion, the temples of Jagannath at Puri and the Sun-temple at Konark were constructed during the reign of the Choda Ganga dynasty in Orissa. These temples are not only architectural marvels but also hold immense religious and cultural significance in Indian history.