SUPER EASY!!!! WILL GIVE BRAINLIEST

How does a barometer work in measuring air pressure?
a.) A barometer has mercury in a dish. Air pressure pushes down on the mercury and forces it up into a glass tube. Thus, the higher the mercury rises in the tube, the higher the air pressure.
b.) A barometer contains fluid that expands or contracts based on the pressure. At a higher pressure, the fluid expands and rises in the tube.
c.) Barometers measure temperature, not pressure.
d.) A barometer contains a fluid that expands or contracts based on the pressure. At a higher pressure, the fluid contracts and lowers in the tube.