Answer: The correct answer is Diffusion.
The molecules of carbon dioxide enter the oceans through the process of diffusion into the surface of sea water and dissolve by a physio-chemical process. The factors affecting the amount of carbon dioxide diffusion includes wind, concentration of carbon dioxide, temperature of the water etc. The carbon dioxide which diffuses into the oceans reacts with water forming carbonic acid, carbonate and bicarbonate ions. The gaseous form of carbon dioxide in atmosphere is converted to non-gaseous form reduces the carbon dioxide pressure in the water and promotes more diffusion from the atmosphere.