The correct answer is: a) Rohu, Catla, Mrigal.
Rohu, Catla, and Mrigal are three of the most important freshwater fish species caught in Bihar. They are all members of the carp family, Cyprinidae, and are native to the Indian subcontinent. Rohu is the largest of the three species, and is a popular food fish. Catla is a smaller species, but is also a popular food fish. Mrigal is the smallest of the three species, and is not as commonly eaten as Rohu or Catla.
Trout, Salmon, and Tuna are all marine fish species, and are not found in freshwater. Hilsa, Pomfret, and Mackerel are also marine fish species, but are found in the Indian Ocean, and are not commonly found in Bihar. Shrimp, Crab, and Lobster are all crustaceans, and are not fish.
Rohu, Catla, and Mrigal are all important food fish in Bihar. They are caught in rivers, canals, and ponds. They are typically caught using nets or traps. Rohu, Catla, and Mrigal are all delicious fish, and are a popular part of the Bihari diet.