Due to the high pressure in this zone, most organisms do not have swim bladders but use other adaptations to maintain neutral buoyancy. in which zone does this occur?

intertidal zone
epipelagic zone
bathypelagic zone
mesopelagic zone

The correct answer is the mesopelagic zone.

Explanation:

The mesopelagic zone gets the amount of sunlight, which is not enough for the process of photosynthesis. Most of the fish in this zone is small, and not as much food is available for them.

They depend on gelatinous flesh for their neutral buoyancy so they don't need the energy to maintain buoyancy. The pressure of swim blade would cause them to rupture hence they can not have swim blades.

c should be the answer