What is meant by 'creep' in relation to climbing ropes?

The term 'creep' in the context of climbing ropes refers to the gradual extension of a rope under load. This phenomenon occurs when a rope is subjected to tension over time, causing it to slowly elongate. This is particularly relevant for dynamic climbing ropes, which are designed to stretch to absorb the impact forces of a fall. Understanding this concept is crucial for climbers as it affects the overall performance of the rope and can influence safety measures during climbs.

In contrast, the other options address different aspects of climbing that do not pertain to the elastic properties of the rope itself. The immediate reaction to a fall relates to the dynamic behavior of the rope at the moment of impact. A form of climbing technique focuses on methods and strategies for climbing rather than on the physical properties of gear. Lastly, rappelling down a surface is a specific descending technique that utilizes ropes but is unrelated to the term 'creep.' Hence, option B accurately captures the essence of what 'creep' means in relation to climbing ropes.