The correct answer is A. 3.
Himachal Pradesh was a Chief Commissioner’s Province from 1948 to 1972. During this time, it was divided into 3 districts: Chamba, Kangra, and Simla.
Chamba district was the largest and most populous district in Himachal Pradesh. It was located in the north of the state, and its capital was Chamba town.
Kangra district was the second largest district in Himachal Pradesh. It was located in the central part of the state, and its capital was Dharamshala town.
Simla district was the smallest district in Himachal Pradesh. It was located in the south of the state, and its capital was Simla town.
In 1972, Himachal Pradesh was granted statehood. At this time, the number of districts in Himachal Pradesh was increased to 10.