The sodden mass killing of fishes is likely to be seen in a

Options

A. mesotrophic lake
B. oligotrophic lake
C. salt lake
D. eutrophic lake

Answer

To solve the question regarding the sudden mass killing of fishes, we need to analyze the characteristics of the given types of lakes and determine which one is most likely to experience such an event.

### Step-by-Step Solution:

1. **Understand the Types of Lakes**:
- **Mesotrophic Lake**: This type of lake has an intermediate level of productivity. It typically has clear water and a balanced ecosystem. The chances of sudden mass fish deaths are low in this type of lake.

- **Oligotrophic Lake**: These lakes are characterized by low productivity and low nutrient content. They usually have very clear water and a low algal population. Similar to mesotrophic lakes, the likelihood of mass fish deaths is minimal here as well.

- **Salt Lake**: Salt lakes have high salinity levels. While they may have unique ecological conditions, they do not typically experience sudden mass fish deaths due to their saline nature.

- **Eutrophic Lake**: This type of lake is characterized by high nutrient levels, particularly phosphorus and nitrogen. Eutrophication leads to excessive algal blooms, which can deplete dissolved oxygen (DO) levels in the water. When the oxygen levels drop significantly, it can lead to hypoxia or anoxia, causing mass mortality of fish and other aquatic organisms.

2. **Conclusion**: Based on the characteristics of each type of lake, the sudden mass killing of fishes is most likely to occur in a **Eutrophic Lake** due to the depletion of dissolved oxygen caused by nutrient overload and subsequent algal blooms.

### Final Answer:
The sudden mass killing of fishes is likely to be seen in a **Eutrophic Lake**.