Which of the following best explains why the diversity of organisms decreases as you move from shallow seas to deep oceans?
answer

the lack of sunlight in the deep ocean limits the types of organisms that can survive.

the levels of oxygen in the deep ocean are too high for many organisms to thrive.

the low temperatures of the deep ocean would freeze most organisms.

the salinity of the deep ocean is too high for most organisms to live.

The correct answer is option A, The lack of sunlight in the deep ocean limits the types of organisms that can survive

Reason –  

Sunlight is very essential for the plant species to survive in the deep ocean. Due to unavailability of sunlight at greater depths in the ocean, marine plants are unable to survive. As the survival of several marine species depends on marine plants, with less or no marine plants at greater depths, very few animal species are able to survive. Also there is lack of oxygen at greater depths, most of the high form of life (which are dependent on oxygen for their survival) are unable to survive in absence or limited supply of oxygen.  

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