What happens to the molar volume when the temperature decreases? Molar volume increases

Molar volume decreases

Molar volume stays the same

molar volume decrease

As you increase the pressure on a gas, its volume will decrease. Think of pushing a piston on a tube of gas. As you decrease the volume, the pressure increases. If you put more volume in a tire, its pressure increases
Your question has to do with Boyle's Law. According to Boyle's Law, the volume and pressure of a gas are inversely proportional (as long as temperature remains constant).
What this boils down to is: if you increase the volume of a gas, its pressure decreases. If you decrease the volume of a gas, its pressure increases.
Good luck with your assignment.