What Situation Relates to the Reason Why Hot-Air Balloons Are

Question

What situation relates to the reason why hot-air balloons are able to fly?
A) Precipitation falls on the leeward side of a mountain.
B) Water droplets can freeze inside clouds.
C) Very little rain falls at 30° north and south of the equator.
D) The tops of hills are warmer than the valleys below.

Accepted Answer

Hot-air balloons are able to fly because hot air rises, and in the case of a hot-air balloon, the air inside the balloon is heated by a burner, making it less dense and causing it to rise. The tops of hills can often be warmer than the valleys below due to differences in elevation and exposure to sunlight, providing an ideal environment for a hot-air balloon to rise.