The correct answer is: Both (A) and (B).
Kohira Dam Project is an irrigation project located in Kaimur district of Bihar. It is a multipurpose project which provides irrigation to an area of 10,000 hectares, drinking water to 100 villages and generates 2.5 MW of power.
Musakund Dam Project is also an irrigation project located in Kaimur district of Bihar. It is a medium irrigation project which provides irrigation to an area of 12,000 hectares.
Both the projects are important for the development of Kaimur district. They provide irrigation to the agricultural land, drinking water to the villages and generate power.