What is the diameter range of a small diameter rope referred to as accessory cord?

Accessory cord is defined as a type of small diameter rope used in various applications like climbing and rescue operations. The standard diameter range for accessory cord is between 3mm and 9mm. This range allows for flexibility, strength, and versatility, making it suitable for tasks such as creating anchors, building (or extending) loops, or performing rescue rigging.

In the context of climbing and other activities, the properties of the cord are essential because the cord needs to be lightweight yet strong enough to handle the loads typically encountered in those scenarios. Cords outside this diameter range would not meet the necessary characteristics that aid in safety and functionality, which is why the other ranges provided do not align with the definition of accessory cord.

The other options indicate diameters that are either too thin, which would not provide enough strength for practical applications, or too thick, thus exceeding the typical specifications for accessory cord.