Standard air is the: a. Mass of 1 cubic meter of dry air at 20°C and atmospheric pressure b. Mass of a cubic meter of air at atmospheric conditions c. Volume of air at ambient temperature and atmospheric pressure d. Volume of 1 kg of dry air at 21°C and atmospheric pressure at sea level or 101.325 kPa e. Volume of 1 kg of air at 15°C and 100 kPa