All motion or changes in an aircraft's attitude occur about which point?

The correct answer is the center of gravity (CG) because it is the point about which an aircraft's mass is evenly distributed. All rotational motion or changes in an aircraft's attitude—such as pitching, rolling, or yawing—occur around this point. The center of gravity is crucial in determining the stability and control of the aircraft. If the CG is located too far forward or too far aft, it can adversely affect the performance and handling characteristics, leading to instability during flight.

The aerodynamic center (AC) is the point where the aerodynamics of the aircraft are balanced but does not directly influence the aircraft's motion in the same way as the CG. Center of pressure (CP) varies with changes in angle of attack and is more related to aerodynamic forces than to the aircraft's mass distribution. The cockpit, while important for pilot operation, does not serve as a reference point for the aircraft's motion in terms of stability or balance. Thus, the center of gravity is the foundational point around which all motions of the aircraft are calculated and executed.