The correct option is C. Lake Malawi. Explanation of the Correct Answer Lake Malawi is primarily a rift lake, which means it was formed as a result of tectonic activity, specifically faulting. The East African Rift System, where Lake Malawi is located, is a tectonic plate boundary where the African continent is splitting into two. This rifting process creates deep valleys and basins, which can fill with water, forming lakes.

1. Formation Process:
2. The rifting occurs when tectonic plates pull apart, causing the land to sink and create a depression. Over time, rainwater and rivers fill these depressions, leading to the formation of lakes.
3. Lake Malawi is one of the largest and deepest lakes in Africa, and its formation is directly linked to this geological process.
4. Geological Evidence:
5. The lake is situated in a graben, which is a block of the Earth's crust that has dropped between two fault lines. This geological structure is characteristic of rift lakes.
6. The presence of unique geological features, such as steep cliffs and deep basins, further supports the idea that Lake Malawi was formed through faulting.

Explanation of Why Other Options Are Incorrect A. Lake Chad: - Lake Chad is a shallow lake located in a low-lying area and is primarily influenced by climatic conditions and river inflow rather than tectonic activity. It has been shrinking due to changes in climate and human activity, but its origin is not due to faulting. B. Lake Superior: - Lake Superior is one of the Great Lakes of North America and was formed by glacial activity during the last Ice Age. The Great Lakes were carved out by glaciers, which is a different process than faulting. While there are some geological features related to faulting in the region, the lake itself is not primarily a result of tectonic activity. D. Lake Victoria: - Lake Victoria is the largest lake in Africa by area and is situated in a basin that was formed by a combination of geological processes, including erosion and sedimentation, rather than faulting. It is not a rift lake and does not owe its origin mainly to tectonic activity. Summary of Key Points

• Lake Malawi is a rift lake formed by tectonic activity and faulting in the East African Rift System.
• The formation of rift lakes involves the sinking of land between fault lines, creating deep basins that can fill with water.
• Other lakes like Lake Chad, Lake Superior, and Lake Victoria have different origins, primarily influenced by climatic conditions, glacial activity, and erosion rather than faulting.
• Understanding the geological processes behind lake formation is crucial for distinguishing between different types of lakes.

Revision Summary

• Lake Malawi is a rift lake formed by faulting in the East African Rift.
• Rift lakes are created when tectonic plates pull apart, leading to the formation of deep basins.
• Other lakes mentioned (Chad, Superior, Victoria) have origins based on glacial activity or climatic conditions, not faulting.
• Recognizing the geological processes is essential for understanding lake formation and classification.