As Atmospheric Carbon Dioxide Levels Have Increased,the Higher Concentration Should

As atmospheric carbon dioxide levels have increased,the higher concentration should increase the diffusion of carbon dioxide into the oceans.However,there is a reduced net rate of carbon dioxide uptake by oceans.Why?

A) This is due to supersaturation of the oceans and the inability of any more carbon dioxide to be assimilated.
B) This is due to decreased atmospheric temperatures that decrease the solubility of carbon dioxide.
C) This is the result of increased atmospheric temperatures that increase the solubility of carbon dioxide.
D) The reduced net rate of carbon dioxide uptake is due to increased surface ocean temperatures that lower the solubility of carbon dioxide.