The correct answer is (b). The Shanan Power House was built in the 1950s. It is one of the oldest hydropower projects in Punjab, India. The power house is located on the Chenab River in the Chamba district of Himachal Pradesh. It has a installed capacity of 300 MW. The power house was built by the Bhakra Beas Management Board (BBMB). It is a run-of-the-river power house. The water for the power house is diverted from the Chenab River through a headrace tunnel. The water then flows through a penstock and strikes a turbine. The turbine rotates a generator, which produces electricity. The electricity is then transmitted to the grid. The Shanan Power House is a major source of electricity for Punjab. It also provides irrigation water to the fields in the region.
The other options are incorrect. The Shanan Power House was not built in the 1930s, 1970s, or 1990s.