The correct answer is: B. specific gravity and dry density.
A pycnometer is a device used to measure the specific gravity of a liquid or solid. It is a small, cylindrical container with a flat bottom and a stopper. The pycnometer is filled with the liquid or solid to be measured, and the mass of the pycnometer and its contents is determined. The pycnometer is then emptied and filled with water, and the mass of the pycnometer and water is determined. The specific gravity of the liquid or solid is then calculated as follows:
Specific gravity = $\frac{Mass of pycnometer + liquid or solid}{Mass of pycnometer + water}$
The dry density of a material is the mass of the material per unit volume of the material. It is calculated as follows:
Dry density = $\frac{Mass of material}{Volume of material}$
The specific gravity of a material is a measure of how dense the material is compared to water. The specific gravity of water is 1.00. A material with a specific gravity greater than 1.00 is denser than water, and a material with a specific gravity less than 1.00 is less dense than water.
The dry density of a material is a measure of how much mass is contained in a given volume of the material. The dry density of a material is important in many engineering applications, such as the design of structures and machines.