Which choice best describes why 90% of all marine organisms thrive/live in the photic zone?

The choice that describes the presence of most of the organisms in the photic zone is because there is presence of sunlight in this region of the ocean

Explanation:

The ocean has many light zones namely the photic zone that has penetration of sunlight, the twilight zone that has very little sunlight penetration and the midnight zone which does not have any penetration of sunlight , since the organisms require sunlight for survival so the marine organisms prefer photic zone of the ocean.

genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).