In unusually cold winters, the northern Black Sea sometimes freezes, while the nearby Adriatic Sea usually doesn't, even if it is just as cold. Freshwater runoff gives the surface of the Black Sea a low salinity of about 18%. What would you guess about the salinity of the Adriatic?
a. Higher than 18%
b. Lower than 18%
c. Exactly 18%
d. Unpredictable
