Concept:Salinity measures the salt content of ocean or sea water.Explanation:The term for the degree of saltiness or the concentration of dissolved salt in oceans and seas is salinity.Salinity is usually expressed in grams per kilogram of water, or in parts per thousand (‰).It varies from one part of the ocean to another due to evaporation, rainfall, and river inflow.Since the definition matches the description in the question, the correct option is salinity of the ocean.Answer:D. salinity of the ocean