Enlist the 2factors which are used in the formation of dry ice

Carbon dioxide is a gas at normal room temperature and atmospheric pressure. Carbon dioxide gas converts into solid carbon dioxide when frozen to a particular temperature with no intermediate liquid phase. This frozen or solidified carbon dioxide is called dry ice. Dry ice is formed when gaseous carbon dioxide is cooled to very low temperatures under high pressure. High pressure brings about condensation of the gas molecules and low temperature solidifies the carbon dioxide gas. Therefore, tow factors that help in formation of dry ice are low temperature and high pressure.

it's filtration, but this is an assumption so my apologies if i got this

it is the most commonly accepted one