Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.

Assertion (A): At greater ocean depths; water moves extremely slow and maintains a uniform low temperature.

Reasons (R): The oceanic surface returns heat and water to the lower atmosphere.

In the light of the above statements, choose the most appropriate answer from the options given below:

Key Points 

• .With respect to temperature, there are three layers in the oceans from the surface to the bottom. 
• The first layer represents the top layer of warm oceanic water and is 500 m thick with temperatures ranging between 20° and 25°C.
• This layer is present within the tropics throughout the year but it develops in mid-latitudes only during summer.
•  The Thermocline layer represents the vertical zone of oceanic water below the first layer and is characterized by the rapid rate of decrease of temperature with increasing depth. 
• The third layer is very cold and extends up to the deep ocean floor.
• The polar areas have only one layer of cold water from the surface (sea level) to the deep ocean floor. 

Hence, the assertion is correct.

Reasons (R): The oceanic surface returns heat and water to the lower atmosphere.

• The major source of the temperature of oceanic water is the Sun.
• The ocean is a significant influence on Earth's weather and climate.
• The ocean covers 70% of the global surface.
• This great reservoir continuously exchanges heat, moisture, and carbon with the atmosphere, driving our weather patterns and influencing the slow, subtle changes in our climate.
• The oceans influence climate by absorbing solar radiation and releasing heat needed to drive the atmospheric circulation, by releasing aerosols that influence cloud cover, by emitting most of the water that falls on the land as rain, by absorbing carbon dioxide from the atmosphere and storing it for years to millions of years. 

Hence, the reason is also correct but does not explain the assertion correctly.