The correct answer is option 'C': Canada.

Canada is credited with the establishment of Uranium City, located in the province of Saskatchewan. Uranium City was established in the mid-1950s as a mining town to support the uranium mining industry in the region.

Here is a detailed explanation:

1. Background of Uranium Mining in Canada:
- Canada is one of the world's leading producers of uranium, a key fuel for nuclear power generation.
- The country has significant uranium deposits, particularly in the province of Saskatchewan.
- Uranium mining in Canada began in the early 1930s and has since played a crucial role in the country's energy sector.

2. Establishment of Uranium City:
- Uranium City was established in the mid-1950s during the peak of uranium mining activities in Canada.
- The town was strategically located near the mining sites to accommodate the growing workforce and provide necessary infrastructure.
- Uranium City served as a hub for mining operations, providing housing, schools, healthcare facilities, and other amenities for the workers and their families.

3. Importance of Uranium City:
- Uranium City played a vital role in the development of Canada's uranium industry.
- The town served as a central point for transporting mined uranium to processing facilities and eventually to nuclear power plants.
- It contributed significantly to the economic growth of the region and provided employment opportunities for the local population.

4. Decline and Closure:
- Over time, the demand for uranium fluctuated, leading to a decline in mining activities in Uranium City.
- As the mining industry faced challenges, the town's population dwindled, and many amenities and services were discontinued.
- Today, Uranium City is considered a ghost town, with only a small number of residents remaining.

In summary, Canada is credited with the establishment of Uranium City in the province of Saskatchewan. The town played a crucial role in supporting the uranium mining industry and contributed to the country's position as a leading producer of uranium. However, with the decline in mining activities, Uranium City has become a ghost town.