WHAT IS SERIOUS PROBLEM OF LAKE BAIKAL IN RUSSIA

33. What is serious problem of Lake Baikal in Russia?A. It contains a rich variety of animals and plants.B. The government did not have the power to enforce laws and regulations.C. It has 1,300 rare species that do not exist anywhere else in the world.D. It is polluted by massive volumes of industrial wastes discharged into it.