According to this passage, the sea _________ is likely to have the lowest salinity.

A．sea water is less salty because fresh water joins in
B．rivers carry industrial exhaust into sea
C．sea ice tend to melt more quickly than in the center of oceans
D．heavy water sinks to the deeper portions of the oceans

A．Typical Oceans and Their Respective Features
B．The Causes of the Changes in Salinity of Ocean Water
C．Different Oceans Have Different Salinity
D．The Precipitation and Evaporation of Oceans