Why Does a Mass of Air Get Cooler as It

Multiple Choice

Why does a mass of air get cooler as it rises over a mountain?

A) The air gets cooler because it loses heat to its surrounding cool air.
B) The air gets cooler because nearby ice and snow are cold.
C) The air gets cooler because the dry air at high elevations conducts heat away easily.
D) Air with a certain amount of heat expands as it rises so that heat is distributed through a larger volume.
E) The air gets cooler because there is more air pressure at the top of the mountain.