The correct answer to this question is option 4: oceans.

The term "biomass" refers to the total weight of living organisms within a given area. In this context, it refers to the combined weight of all living organisms in the world. The majority of this biomass is found in the oceans.

Oceans cover about 70% of the Earth`s surface and are home to a vast number of species. They support a wide range of marine life, including microscopic organisms, fish, marine mammals, and coral reefs. These organisms contribute to the overall biomass of the planet.

While tropical rain forests, freshwater wetlands, and topsoils are all important ecosystems that support various forms of life, they do not contain as much biomass as the oceans. Oceans have a larger volume and a greater variety of species, which ultimately contribute to their higher biomass.

It is important to note the significance of the oceans in terms of global biodiversity and their role in regulating the Earth`s climate. They play a vital role in supporting life on our planet and are essential for human survival.

Alert - The correct answer should be option 1: tropical rainforests. Tropical rainforests are known to have the highest biomass density of any ecosystem on Earth. They contain