Choose the correct answer:

The temperature of the ocean waters generally_______ at greater depth.

OPTION A is incorrect because the temperature of the ocean does not increase with depth as there is limited sunlight and no salinity.

OPTION B is correct because the temperature of the ocean decreases with greater depth due to lesser salinity and lack of sunlight.

OPTION C is incorrect as the temperature of the ocean varies according to latitude and salinity, and never remains constant.

OPTION D is incorrect as there is a correct option (Option B)

To Keep in Mind

The temperature drop in the ocean is less gradual near the surface, as salinity and sunlight plays its part. The sunlight keeps the surface water warm, and the salinity reduces the freezing temperature of water.

As the depth increases, effects of both the sunlight and water salinity are substantially minimised, hence pressure and depth make the temperature drop in the lower depths.

It will be useful to understand the concept of Thermocline; it is the zone in the ocean where there is sudden temperature drop in temperature with depth, and effectively separates the surface above from the deep sea below.