Among the given options, the type of forest that exhibits the highest biodiversity is the Tropical Rainforest (option 2).

Option 1, Dry deciduous forest, refers to a type of forest that loses its leaves during the dry season. These forests are typically found in regions with a distinct dry season and do not have as high a biodiversity as tropical rainforests.

Option 3, Moist deciduous forest, refers to a type of forest characterized by trees that shed their leaves for a part of the year. These forests are found in regions with a moderate amount of rainfall. While they can support relatively diverse ecosystems, they do not have the same level of biodiversity as tropical rainforests.

Option 4, Mangrove forest, refers to a type of coastal forest that is dominated by salt-tolerant trees. Mangrove forests are important ecosystems that provide a habitat for various species, but they generally have a lower biodiversity compared to tropical rainforests.

Tropical rainforests, on the other hand, are characterized by high annual rainfall and a consistently warm climate. These forests have a wide range of plant and animal species, making them the most biodiverse ecosystems on Earth. Therefore, the correct answer is option 2, Tropical rainforest.