Answer: the carpet padding
Explanation:
Individual evidences are simply refered to as properties of physical evidence that has to a high degree of certainty for a common source. For individual evidences, the suspect is being narrowed down to a single individual. Examples include fingerprints, toolmarks etc.
In the question above, the example of individual evidence when it comes to carpet will be the carpet padding. While other options such as fiber length, dye composition and the type of fiber can still relate to other things, carpet padding narrows it down to carpet.
