Which of the following speeds is directly related to aircraft landing gear operation?

The speed that is directly related to aircraft landing gear operation is the maximum landing gear extension speed. This speed, often denoted as V_LO, specifies the highest speed at which the landing gear can safely be deployed without risking structural damage or malfunction. Exceeding this speed during the landing gear extension process can lead to mechanical failure or hinder the proper functioning of the gear system.

In contrast, minimum control speed with critical engine inoperative pertains to the speed required to maintain controllability of the aircraft in the event of an engine failure, which does not specifically involve the landing gear operation. The never exceed speed indicates the maximum speed that should not be exceeded under any circumstances to prevent damage to the aircraft, but it is not specifically tied to landing gear operation. Lift off speed, while critical for takeoff, relates to the speed at which the aircraft can safely take flight and does not address the deployment or retraction of landing gear. Therefore, maximum landing gear extension speed is the most relevant to the operation of the landing gear itself.