Answer the following question given this paragraph: 

In this lesson, you read that air density and pressure change with altitude. The temperature of the air also changes with altitude. Air temperature measures the heat energy of air molecules.


Q: What does temperature measure?

 Choices:

- lowest kinetic energy of molecules

- average potential energy of molecules

- highest potential energy of molecules

- average kinetic energy of molecules

A:
average kinetic energy of molecules
