These characteristics apply to evidence that can be associated with a common source with high probability.

The correct choice is individual characteristics, as these refer to unique features that can be directly linked to a particular source or individual with a high degree of certainty. Individual characteristics are distinct traits or markings that set something apart from all other sources. For instance, in forensic science, fingerprints or specific wear patterns on a tool can identify a unique origin, making it possible to associate the evidence with a single person or object confidently.

In contrast, general characteristics and class characteristics refer to features that are common among groups of items or sources. Class characteristics can include traits shared by all members of a particular category, such as the tread patterns of a specific brand of shoe, which cannot definitively link evidence to one individual but rather to a group. Personal characteristics often relate to broader features that might apply to a group of individuals but do not lend themselves to the same certainty as individual characteristics.