The correct answer is (c). Rana Kumbha was a Rajput ruler of Mewar who is known to have written a book on music called Sangeet Ratnakar. The book is a treatise on Indian classical music and includes discussions on the theory and practice of music, as well as biographies of famous musicians.
Jayachandra Gahadavala was a Rajput ruler of Kanauj who was defeated by Muhammad Ghori in the Battle of Chandawar in 1194. Prithviraj Chauhan was a Rajput ruler of Ajmer and Delhi who was also defeated by Muhammad Ghori in the Battle of Tarain in 1192. Man Singh was a Rajput ruler of Amber who served as a general in the Mughal army.
Sangeet Ratnakar is a valuable source of information on Indian classical music. It is one of the earliest surviving treatises on the subject and provides insights into the musical practices of the time. The book is also notable for its beautiful prose and poetic style.