Which of the following is NOT an authorized female hairstyle?

Eccentric hairstyles are not authorized for female soldiers because the Army's standards focus on maintaining a uniform and professional appearance. Hairstyles that are considered eccentric can vary greatly and may draw unnecessary attention or can be seen as unkempt, which goes against the Army's values of discipline and uniformity.

In contrast, long ponytails, neatly styled chignons, and standard braids align with the Army's grooming standards, as they can be kept neat and presentable while still allowing for personal expression within the guidelines. The regulations emphasize that hair should be arranged in a manner that is neat, conservative, and in line with military standards, which is why the other options are acceptable.