The correct answer is: A. U. S. Parmar.
U. S. Parmar is a historian and author who specializes in the history of the Gurkhas. He is the author of several books on the subject, including “Gurkha Conquest of Arki”.
The book “Gurkha Conquest of Arki” is a historical account of the Gurkha conquest of the Arki kingdom in 1815. The book provides a detailed account of the military campaign, as well as the political and social context of the conquest.
The book is well-researched and well-written. It is an important source of information on the Gurkhas and their history.
The other options are incorrect.
B. Ram Rahul is a historian and author who specializes in the history of India. He is the author of several books on the subject, including “The History of India”.
C. Vikram Kayasth is a historian and author who specializes in the history of Nepal. He is the author of several books on the subject, including “The History of Nepal”.
D. Shanta Kumar is a politician and former Chief Minister of Himachal Pradesh. He is not an author.