What is the lowest point of land on Earth?

The lowest point of land on Earth is found at the shore of the Dead Sea, which is situated at more than 400 meters (about 1,300 feet) below sea level. This unique geographical feature arises from the fact that the Dead Sea is situated in a rift valley and is a saline lake that does not contain any outlets, leading to the accumulation of minerals and water that contributes to its low elevation.

In contrast, while the Mariana Trench and Challenger Deep are indeed the deepest points in the world's oceans, they are not considered "land" as they are both underwater features. The Mariana Trench is the deepest oceanic trench in the world, and Challenger Deep is its deepest part. Lake Baikal, while it is a significant body of water and the deepest freshwater lake on Earth, is not at a lower elevation than the Dead Sea shore. Therefore, the Dead Sea shore is recognized as the lowest point of exposed land on Earth's surface, making it the correct choice.