The correct answer is: C. 26 Shimla hill states, 4 Punjab hill states
Himachal Pradesh was formed on 15 April 1948 by the merger of 26 princely states of the Shimla Hill States Agency and four princely states of the Punjab Hill States Agency. The 26 Shimla Hill States were:
- Baghal
- Bashahar
- Bhadrawah
- Chamba
- Churah
- Dadhwal
- Dehra
- Guler
- Hamirpur
- Jubbal
- Kangra
- Kinnaur
- Kullu
- Lahaul and Spiti
- Mandi
- Mankot
- Masrur
- Nalagarh
- Nurpur
- Rampur Bushahr
- Sirmaur
- Suket
- Theog
- Tira Sujanpur
The four Punjab Hill States were:
- Chamba (part)
- Dalhousie
- Kangra (part)
- Mandi (part)
The merger of these states was a result of the Instrument of Accession, which was signed by the rulers of the princely states with the Government of India on 15 August 1947. The Instrument of Accession granted the Government of India control over the external affairs, defense, and communications of the princely states.
The merger of the princely states into Himachal Pradesh was a significant event in the history of the state. It marked the beginning of a new era of development and progress for the people of Himachal Pradesh.