The correct answer is (c) Chamoli.
The Valley of Flowers National Park is a national park in the Indian state of Uttarakhand. It is located in the Garhwal Himalayas, in the Chamoli district. The park is known for its alpine meadows, which are home to a variety of flowers, including blue poppies, edelweiss, and Brahma kamal. The park is also home to a variety of animals, including snow leopards, Himalayan tahr, and musk deer.
The Valley of Flowers was declared a national park in 1982. It is a UNESCO World Heritage Site.
The other options are incorrect.
(a) Rudraprayag is a district in the Indian state of Uttarakhand. It is located in the Garhwal Himalayas. The district is home to the Kedarnath Temple, one of the Char Dham pilgrimage sites.
(b) Pithoragarh is a district in the Indian state of Uttarakhand. It is located in the Kumaon Himalayas. The district is home to the Nanda Devi National Park, a UNESCO World Heritage Site.
(d) Uttarkashi is a district in the Indian state of Uttarakhand. It is located in the Garhwal Himalayas. The district is home to the Gangotri Temple, one of the Char Dham pilgrimage sites.