The correct answer is option 2 - Very polluted. BOD stands for Biochemical Oxygen Demand. It is a measure of the amount of dissolved oxygen needed by microorganisms in water to break down organic material. High BOD values indicate a large amount of organic matter present in the water. This organic matter comes from sources like sewage, industrial waste, or agricultural runoff. When there is a high BOD, it means that there is a high concentration of pollutants in the water, as these organic materials are often pollutants themselves or they consume oxygen needed by aquatic organisms. This can lead to a decrease in dissolved oxygen levels, which is harmful to aquatic life and indicates poor water quality. Therefore, a high BOD value generally indicates that the water body is very polluted.