1. What is an air mass? A. A small body of air that develops over time.
B. A large body of wind that makes up the Earth.
C. large body of air that has properties similar to the part of Earth's surface over which
it develops.

“An air mass is a large body of air whose properties of temperature and humidity are similar in any horizontal direction.”

So, the answer is C.

Have a great day/night and stay safe! :)

c hydrophobia is the answer

i believe the answer is d : )