The correct option is A Mass/Volume
Density is a measure of how tightly a certain amount of matter is packed into a given volume. The more the stuff is packed in, higher is the density. Density can be calculated by dividing an object’s mass by its volume. It is commonly measured in grams per millilitre or grams per cubic centimetre.
Ocean density varies from place to place because it is affected by salinity and temperature. This means that ships float higher or lower in the water, depending on the density of the ocean.