Final answer:
The border of a sterile field is considered noncritical, meaning it does not need to be sterile, can be touched with clean hands, and is not part of the sterile field itself.
Step-by-step explanation:
The border of a sterile field plays a critical role in maintaining the sterility of the area and preventing contamination. The correct answer to the question regarding the border is that it is considered noncritical. This means that the border itself does not need to be sterile, as it does not come into contact with the sterile items or areas inside the central sterile field. Therefore, the border can be touched with bare hands, provided that the hands are clean and do not intrude upon the sterile area within. Keeping the border moist is not recommended as moisture could compromise the sterility of the field, and it is erroneous to consider the border part of the sterile field itself.