The correct answer is B. Mass.
Mass is a measure of how much matter is in an object. It is a fundamental property of matter, and it does not change with location or motion. Weight is a measure of the force of gravity on an object. It is equal to the mass of the object times the acceleration due to gravity. Density is a measure of how much mass is in a given volume. It is equal to the mass of an object divided by its volume.
In the case of a ball of steel, the mass is the same regardless of where
it is located or how fast it is moving. The weight of the ball of steel will change depending on the strength of the gravitational field it is in. The density of the ball of steel will depend on the type of steel it is made of and its shape.Here is a table that summarizes the differences between mass, weight, and density:
| Property | Description |
|—|—|
| Mass | A measure of how much matter is in an object. |
| Weight | A measure of the force of gravity on an object. |
| Density | A measure of how much mass is in a given volume. |