Which of the following is considered a fixed empennage component?

The vertical stabilizer is considered a fixed empennage component because it provides stability and helps maintain the aircraft's directional control. Unlike movable components such as the rudder and elevator, which can move to change the aircraft's pitch and yaw, the vertical stabilizer remains stationary during flight. Its primary function is to prevent unwanted yawing motion and to provide a surface against which the rudder can exert force to facilitate directional changes.

In contrast, the rudder and elevator are both components that can move to control the aircraft's attitude. Trim tabs are also movable and are used to adjust the control surfaces for fine-tuning the aircraft's flight characteristics, but they are not fixed components in their design. Therefore, the vertical stabilizer stands out as a key structural element that provides essential aerodynamic stability to the aircraft.