The correct answer is that both molecular motion, pressure and temperature increase as volume reduces.
Explanation:
A reduction in volume changes the molecular motion, temperature and pressure of the system. When the volume of the container decreases, this causes the pressure to increase, the temperature to increase and the molecular motion to increase. This is because a liquid and a solid are incompressible, so by reducing the volume of a gas, the molecules increase their movement as the temperature of the system increases, which is due to the increased pressure applied to reduce the volume of the system.
If the mass stays constant the object's density decreases as the volume increases. ... Because the property of density is a constant for all variables, density can be used to identify the material an object is made of.