The correct answer is A. Govind Sagar.
Govind Sagar is the largest artificial lake in Himachal Pradesh. It is located in Bilaspur district and was created by the construction of the Bhakra Dam on the Sutlej River. The lake is 51 km long and 8 km wide, and has a surface area of 516 km2. It is a popular tourist destination, and is known for its scenic beauty and water sports.
Nako Lake is a small lake located in Kinnaur district. It is a popular tourist destination, and is known for its Buddhist temples and monasteries.
Pandoh Lake is a small lake located in Kangra district. It is a popular tourist destination, and is known for its fishing and boating.
Manimalesh Lake is a small lake located in Mandi district. It is a popular tourist destination, and is known for its wildlife.