What does the term 'transient' refer to in physical evidence?

The term 'transient' in the context of physical evidence refers to something that lasts for only a short time or is impermanent. This concept is critical in forensic science because transient evidence can include impressions, marks, or conditions that may change quickly due to environmental factors or disturbances. For example, footprints in the snow or tire tracks that could be easily erased by rain or other activities would be considered transient evidence. Recognizing and documenting this type of evidence promptly is essential, as it may not be available for analysis later. The other options pertain to different characteristics of evidence and do not capture the essence of what "transient" signifies in forensic contexts.