During a normal crosswind landing on a runway, what must be true at the moment of touchdown?

When landing in a crosswind, it is crucial for the aircraft's longitudinal axis to be aligned with the runway upon touchdown. This alignment ensures that the aircraft lands directly on the centerline, optimizing stability and control. Ideally, the aircraft's movement direction during landing should be in line with the runway, which helps in maintaining appropriate control and preventing undesired lateral movement. This parallel alignment minimizes the risk of the aircraft drifting off the runway heading, which can result from the influence of crosswinds during the landing phase.

Other options may involve valid techniques for managing crosswinds, such as adjusting the angle of the wings or controlling the aircraft's pitch, but they do not capture the essential requirement of ensuring the aircraft's longitudinal axis is aligned with the runway at touchdown. Thus, maintaining this alignment fundamentally supports safe and effective crosswind landing procedures.