What type of air mass is typically associated with dry conditions on the leeward side of mountains?

The correct answer, dry air, pertains to the phenomenon known as the rain shadow effect, which occurs when moist air rises over a mountain range. As the air ascends, it cools and loses its moisture in the form of precipitation on the windward side of the mountains. This leaves the air drier as it descends on the leeward side.

As the air descends, it warms up, further reducing its relative humidity and leading to arid or dry conditions. This process explains why the leeward side of mountains often experiences significantly less rainfall and is more susceptible to dry air conditions. Thus, dry air is characteristic of these areas, making it the correct response to the question regarding the type of air mass typically associated with dry conditions on the leeward side of mountains.