What factor contributes to an aircraft's wake turbulence?

Wake turbulence is primarily caused by the weight of an aircraft, which generates vortices as it moves through the air. Heavier aircraft create stronger wake turbulence due to the more significant disturbance in the air they produce. Cleanliness refers to the aerodynamic efficiency of the aircraft, which can impact how smoothly air flows over its surfaces, potentially affecting the strength of the wake. Speed plays a role as well; faster aircraft tend to generate more turbulent wake as they displace air more rapidly.

The combination of these factors—weight (which directly correlates to the strength of the vortices), cleanliness (which affects the overall drag and airflow), and speed (how quickly they move through the air)—provides a comprehensive understanding of what contributes to wake turbulence. Thus, this choice accurately encompasses these essential factors in determining the intensity and behavior of wake turbulence created by an aircraft.