Final answer:
Rapid changes in temperature and humidity are not a characteristic of an air mass.
Step-by-step explanation:
D) Rapid changes in temperature and humidity
Out of the given options, rapid changes in temperature and humidity are not a characteristic of an air mass. Air masses are characterized by a) uniform temperature and humidity, b) large and homogeneous, and c) stationary in nature. Rapid changes in temperature and humidity are more indicative of weather fronts, which are the boundaries between air masses.