The correct answer is: C. The Presidential Order, 1971.
The office of Lt Governor has come to an end by the Presidential Order, 1971. The Presidential Order was issued on 26 January 1971, and it came into effect on 27 January 1971. The Presidential Order abolished the office of Lt Governor of Himachal Pradesh, and it also transferred the powers and functions of the Lt Governor to the Governor of Himachal Pradesh.
The Presidential Order was issued in accordance with the provisions of Article 371 of the Constitution of India. Article 371 provides special provisions for the state of Himachal Pradesh. One of the special provisions is that the President can, by order, direct that the executive power of the state shall be exercised by the Governor, either directly or through officers subordinate to him.
The Presidential Order, 1971 was issued in exercise of the powers conferred by Article 371 of the Constitution of India. The Order abolished the office of Lt Governor of Himachal Pradesh, and it also transferred the powers and functions of the Lt Governor to the Governor of Himachal Pradesh.
The Presidential Order, 1971 was a controversial move. Some people argued that the Order was unnecessary, and that the office of Lt Governor could have been retained. Others argued that the Order was a necessary step to ensure the smooth functioning of the government in Himachal Pradesh.
The Presidential Order, 1971 remains in force today. The office of Lt Governor has not been revived, and the powers and functions of the Lt Governor are exercised by the Governor of Himachal Pradesh.