Correct Option: D

Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass w/ gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.