Which of the following measures of humidity is NOT affected by change in pressure and temperature?

Correct option is C

Specific humidity is the measure of the mass of water vapor present per unit mass of air (including the water vapor). It is not affected by changes in pressure or temperature because it is a ratio of water vapor mass to the total mass of the air parcel. Unlike other humidity measures, specific humidity remains constant as long as the amount of water vapor and total air mass do not change.
Information Booster:
· Relative humidity depends on temperature as it is the ratio of actual water vapor pressure to the saturation vapor pressure at a given temperature.
· Vapour pressure varies with temperature since it represents the pressure exerted by water vapor molecules in the air.
· Absolute humidity is the mass of water vapor per unit volume of air, which changes with both temperature and pressure variations.