As ocean depth increases, temperature increases density decreases salinity increases pressure decreases

The correct option is: salinity increases  

Explanation:

Ocean is a large water body that is a division of the World Ocean. An ocean is divided into various vertical zones based upon the physical and biological conditions.

The halocline zone is characterized by a rapid increase in the salinity with the increase in the depth. Thus resulting in decrease in the temperature of maximum density with the increase in salinity.

the answer is 303.15 or 303