The correct answer is: C. Nilmata Purana.
The Nilmata Purana is a Hindu text that describes the history and geography of Kashmir. It is one of the most important texts on Kashmir Shaivism, a form of Hinduism that is practiced in Kashmir. The Nilmata Purana states that Kashyap Mar, representing modern day Kashmir, was created by the sage Kashyapa. The sage Kashyapa was one of the seven sages who were born from the mind of Brahma, the creator god. Kashyapa Mar is said to be a beautiful land with lush forests, clear lakes, and snow-capped mountains. It is a land of great natural beauty and spiritual significance.
The other options are incorrect. The Rajatarangini is a chronicle of the history of Kashmir. The Rajadarshini is a Sanskrit poem that describes the beauty of Kashmir. The Braht Samhita is a Hindu text that deals with astronomy, astrology, and mathematics.