The correct answer is A. Kalhana.
Rajatarangini is a chronicle of the kings of Kashmir, written in Sanskrit by Kalhana in the 12th century. It is considered one of the most important works of medieval Indian literature. The work is divided into eight books, covering the period from the founding of Kashmir to the reign of Jayasimha.
Alberuni was a Persian scholar who visited India in the 11th century. He wrote a number of works on Indian history, religion, and culture, including Kitab al-Hind (The Book of India).
Harsha Vardhana was an Indian emperor who ruled over much of northern India in the 7th century. He was a patron of the arts and literature, and is known for his military conquests.
Kautilya was an Indian statesman and philosopher who lived in the 4th century BC. He is best known for his work Arthashastra, a treatise on statecraft and economics.