Questions: The majority of biodiversity in Antarctica is found in .

The answer is the second one: the waters surrounding the continent.

Explanation for each option:

1. The animals that use Antarctica as part of their migration route: While many animals, such as certain bird species and marine mammals, do use Antarctica as part of their migration routes, the majority of biodiversity is not found in these migratory animals alone.

2. The waters surrounding the continent: This is the correct answer. The Southern Ocean surrounding Antarctica is rich in biodiversity, including a wide variety of marine life such as krill, fish, seals, and whales. The ocean's nutrient-rich waters support a complex and diverse ecosystem.

3. Its plant life: Antarctica's plant life is limited due to the harsh climate. Only a few species of mosses, lichens, and algae are found, and they do not represent the majority of biodiversity.

4. Its insect life: Insect life in Antarctica is extremely limited, with only a few species adapted to survive the extreme conditions. Therefore, it does not account for the majority of biodiversity.

In summary, the majority of biodiversity in Antarctica is found in the waters surrounding the continent, which support a rich and diverse marine ecosystem.