How can air be lifted?

Air can be lifted through several mechanisms, and option C outlines three specific processes that effectively lift air: frontal lifting, orographic lifting, and convective lifting.

Frontal lifting occurs when a warm air mass rises over a colder air mass due to differences in temperature and density. This often happens along weather fronts, where the interaction of air masses leads to lifting and subsequent cloud formation.

Orographic lifting describes the process where air is forced to rise over mountains or elevated terrain. As the air ascends, it cools and can lead to cloud formation and precipitation on the windward side of the mountain, while creating drier conditions on the leeward side, known as the rain shadow effect.

Convective lifting is the process where localized heating of the Earth's surface causes warmer air to rise. The heated air becomes less dense and ascends through the cooler surrounding air, often leading to the development of cumulus clouds and, potentially, thunderstorms.

In contrast, the other options either focus on incomplete lifting methods or incorrectly emphasize single elements, such as heating the air alone, which is typically part of the convective process but not a standalone mechanism for lifting air. Similarly, wind velocity pertains more to the horizontal movement of air rather than specific lifting techniques.