The correct answer is option 'C' - Dehradun.

The Imperial Forest Institute was indeed set up in Dehradun. Let's delve into the details to understand why Dehradun was chosen as the location for this prestigious institute.

1. Historical Context:
During the British colonial period, the need for systematic management of forests in India was recognized. The British government realized that forests played a crucial role in the economic and strategic development of the country. To address this, they established the Imperial Forest Department in 1864, which aimed to conserve and manage forests in a sustainable manner. As part of this initiative, the Imperial Forest Institute was established in Dehradun.

2. Geographical Advantage:
Dehradun, the capital city of Uttarakhand in northern India, was chosen as the location for the Imperial Forest Institute due to its favorable geographical features. The city is nestled in the foothills of the Himalayas and is surrounded by dense forests. This made it an ideal location for studying and researching various aspects of forestry. The presence of diverse flora and fauna in the region provided ample opportunities for practical fieldwork and research.

3. Access to Forest Resources:
Dehradun's proximity to vast forest resources also played a significant role in the establishment of the Imperial Forest Institute. The region is known for its rich forest cover, including the famous Sal forests of the Shivalik Hills. This allowed the institute to have easy access to different forest types and study their ecology, management practices, and utilization methods.

4. Education and Research Hub:
Dehradun had already gained recognition as an educational and research hub during the colonial period. The city was home to several renowned institutions, including the Forest Research Institute (FRI), which was established in 1906. The presence of such institutions created a conducive environment for the growth of forestry-related education and research in Dehradun.

5. Government Support:
The British government's support and investment in forestry education and research in Dehradun further solidified its position as the ideal location for the Imperial Forest Institute. The government recognized the importance of trained forest professionals and provided resources to establish and develop the institute.

In conclusion, the Imperial Forest Institute was set up in Dehradun due to its historical context, favorable geographical features, access to forest resources, the presence of other educational institutions, and government support. These factors made Dehradun an ideal location for the institute to carry out research, education, and training in the field of forestry.