Which of the following processes will increase salinity of ocean waters

A．The precipitation and evaporation of oceans.
B．The causes of the changes in salinity of ocean water.
C．Different oceans in tropical and coastal regions.
D．The formation and melting of sea ice.

A．is a good example of increased salinity in freezing sea water
B．is much larger in area than the Arctic oceans
C．has a much lower salinity now than ever
D．has the denser water in its upper parts