Answer: (Detailed Solution Below)
Option C: Diu
Detailed Solution:
The correct answer is “Diu”.
The Union Territory of Diu is the first UT in India to run 100% on solar energy. In 2018, Diu became the first Indian city to be entirely powered by solar energy during the day. The solar power plant in Diu has a capacity of 13 megawatts and is spread over 50 hectares. The electricity generated from the solar plant is sufficient to power the entire city during the day, and the surplus power is exported to the national grid. This has helped Diu to reduce its carbon footprint and become a green city.