Which of the following best describes a characteristic of wake turbulence?

Wake turbulence refers to the disturbed air that is generated by an aircraft as it moves through the atmosphere, particularly from the lift-producing devices such as wings. The correct assertion emphasizes that wake turbulence can indeed influence aircraft operating on nearby runways. When an aircraft takes off or lands, it produces vortices, which can linger in the air for several minutes after the aircraft has passed, depending on various factors such as weight, wind conditions, and temperature.

As a result, smaller aircraft that are taking off or landing in proximity to larger aircraft may encounter these vortices, which can lead to unexpected and potentially dangerous situations. This characteristic underscores the need for proper separation distances between different types of aircraft during operations on parallel runways or the same runway.

The other options suggest misunderstandings of wake turbulence dynamics. For instance, it's not true that wake turbulence dissipates immediately after takeoff; instead, it can persist for some time, affecting subsequent aircraft. Additionally, it poses risks not just during cruising altitudes but prominently during takeoff and landing phases. Lastly, while larger aircraft do produce more significant wake turbulence, it is a concern for all sizes of aircraft under certain conditions, thus indicating that wake turbulence is not exclusive to larger aircraft alone.