Answer:I think it is 'A'
Explanation:
Because when mesocline is a really a known word. Also, when you search what it is. It is a different word. Mixed layer obviously doesn't make sense. And deep ocean most likely mean the trenches. But pycnocline is a layer in an ocean in which the density increases rapidly with depth. P.S. sorry if I'm wrong. This is the best I can give you.
Pynocline is the middle layer of ocean. Thus, option A is correct.
Study of oceans is known as oceonography & oceonographers ( scientist who study the ocean ) divided the ocean into several part from top to bottom i.e in horizontal layers.
The characteristics which distinguish the the ocean into different layers are temperature, density and amount of light at different depth to classify these layers. The most important factor is density of water which is determined by salinity of water.
Oceonographers are generally categories the ocean into four layer:-
1:- Epipelagic zone
This zone refers to the surface of the ocean where light penetrates first.
2:- Mesopelagic Zone
The mesopelagic zone is found from 150mtr to 1000mtr below the surface also called as twilight zone
3:- Bathypelagic Zone
This zone is found from 1000mtr to 4000mtr below the surface of ocean in thus region light is not exist.
4:- Abyssopelagic Zone
This zone is found from 4000mtr to the surface of seafloor in this zone water are nearly freezing and pressure are immense.
Therefore, pynocline is the middle layer of ocean. Thus,option A is correct.
Learn more about pynocline here:
https://brainly.com/question/9175266
#SPJ5
