Answer:
The correct answer is option D.
Step-by-step explanation:
Thermohaline circulation is the circulation of currents in the deep ocean due to the density of the water which is controlled by heat and salinity. Water in the ocean posses layers or defined boundaries based on the density which provides driving force to the deep ocean currents.
Formation of these layers is due to the sinking of the cold water in the basin which and ice formation which leaves the salt in the seawater ,therefore, increasing salinity. This increased salinity increases its density and the surface water is replaced by the sinking water causing deep ocean currents.
Thus, option D is the correct answer.