The correct answer is: B. Mandi
Mandi district is famous for salt mines. The salt mines are located in the town of Mandi, which is the district headquarters. The salt mines are a major tourist attraction in the district.
The salt mines are a part of the Himalayan salt range. The salt mines are formed by the evaporation of seawater. The salt mines are a major source of salt for the people of Himachal Pradesh.
The salt mines are also a major source of employment for the people of Mandi district. The salt mines are a major tourist attraction in the district.
The other options are incorrect because they are not famous for salt mines.
A. Kullu is famous for its apple orchards.
C. Solan is famous for its apple orchards and its scenic beauty.
D. Bilaspur is famous for its temples and its historical importance.