What is a requirement for cadets regarding the grooming of hair?

Grooming standards for cadets, especially in military or drill competition settings, typically emphasize discipline and uniformity in appearance. The requirement that no hair should touch the collar is established to maintain a neat and professional look. It ensures that each cadet presents a uniform appearance that is consistent with the expectations of military decorum and discipline.

This guideline helps to prevent distractions both for the cadet and their teammates during drills, as well as creating a cohesive impression when in formation or engaged with the public. By adhering to this standard, cadets demonstrate respect for their uniform and the organization they represent, which is a core value in military and drill training.

The other choices, while they may be true in certain contexts, do not align with the broad, general requirement regarding hair grooming applicable to all cadets.