Concept:Gas thermometers are the most accurate type for temperature measurement because their pressure change is directly and reproducibly related to temperature over a wide range.
Explanation:Liquid-in-glass thermometers, such as mercury, clinical, and alcohol thermometers, depend on the expansion of a liquid. This expansion is not perfectly uniform and can be affected by impurities and capillary action.
A gas thermometer, however, measures temperature using the relationship between pressure and temperature of a gas at constant volume. Gases behave more consistently and their pressure-temperature relationship is highly linear.
Because gases have a much lower coefficient of expansion variation than liquids and respond very precisely to small temperature changes, gas thermometers give the most reliable and accurate readings. Therefore, for accurate measurement of temperature, a gas thermometer is preferred over liquid-based thermometers.
Answer:B. gas thermometer