The correct answer is (c) Dehradun.
Dehradun was the capital of British Garhwal from 1815 to 1947. It was chosen as the capital because it was a central location in the region and was easily accessible from both the plains and the hills. Dehradun also had a strong military presence, which was important for the British as they sought to control the region.
Pauri was the capital of Garhwal before the British took control. It is located in the Garhwal Himalayas and is a popular tourist destination.
Tehri is a city in the Garhwal Himalayas and is the current capital of Uttarakhand. It is a major tourist destination and is home to a number of temples and monasteries.
Nainital is a town in the Kumaon Himalayas and is a popular tourist destination. It is known for its scenic beauty and its lake.