The correct answer is: D. Premchand Jain.
Premchand Jain was the first Advocate General of Haryana. He was appointed to the position on 1 November 1966 and served until 31 October 1972. He was a prominent lawyer and politician who played a significant role in the formation of the state of Haryana.
A. Krishna Murari was a judge of the Punjab and Haryana High Court. He was not the first Advocate General of Haryana.
B. D. K. Jain was a judge of the Supreme Court of India. He was not the first Advocate General of Haryana.
C. Babu Anandswarup was a politician who served as the Chief Minister of Haryana from 1967 to 1968. He was not the first Advocate General of Haryana.