The correct answer is (a) Mussoorie.
Mussoorie is a hill station in the Garhwal Himalayas in the Indian state of Uttarakhand. It is a popular tourist destination, known for its scenic views, colonial architecture, and mild climate. The town was founded in the 19th century by the British, who used it as a summer capital of the United Provinces of Agra and Oudh (now Uttar Pradesh).
Ranikhet is another hill station in Uttarakhand, located about 120 kilometers from Dehradun. It is a popular destination for trekking, hiking, and camping. The town was founded in the 19th century by the British, who used it as a sanatorium for soldiers suffering from tuberculosis.
Nainital is a lake town in the Kumaon Himalayas in the Indian state of Uttarakhand. It is a popular tourist destination, known for its scenic views, boating, and water sports. The town was founded in the 19th century by the British, who used it as a summer capital of the Kumaon Division.
Dehradun is the capital of Uttarakhand. It is a major educational and cultural center, and is home to several universities and colleges. The city was founded in the 16th century by the Chand dynasty, and was later ruled by the Gorkhas and the British.