The correct answer is (b), Dehradun.
Chandpur Garhi, Devalgarh, and Srinagar were all capitals of the Parmar rulers of Garhwal. Dehradun was not a capital of the Parmar rulers of Garhwal.
Chandpur Garhi was the first capital of the Parmar rulers of Garhwal. It was located in the present-day district of Tehri Garhwal. Devalgarh was the second capital of the Parmar rulers of Garhwal. It was located in the present-day district of Chamoli Garhwal. Srinagar was the third and final capital of the Parmar rulers of Garhwal. It is the present-day capital of the state of Uttarakhand.
The Parmar rulers of Garhwal were a Rajput dynasty that ruled the Garhwal region of India from the 11th to the 18th centuries. They were originally from the Gurjar Pratihara dynasty, which ruled much of northern India from the 7th to the 11th centuries. The Parmar rulers of Garhwal were a powerful and influential dynasty, and they played a significant role in the history of the Garhwal region.