Final answer:
To measure the density of an object, mass and volume must be measured. Density is calculated as mass divided by volume and is an intensive property that does not change with the amount of the substance.
Step-by-step explanation:
To determine the density of an object, the two properties that need to be measured are mass and volume. The density of an object is calculated by dividing its mass by its volume. This means that if you have the mass of an object, which can be found directly by weighing it, and the volume of an object, which can be found directly or indirectly (for example, via length measurements of a regular shape or by water displacement for an irregular shape), you can calculate its density.
Density is an intensive property, meaning it does not change with the amount of substance present. This is why objects made of the same material but different sizes, such as a large block of iron and a small iron nail, will have the same density.
The formula for density, therefore, is d = m/V, where d is density, m is mass, and V is volume. To answer the student's question, the correct option to measure density is a) The mass and the volume.