Which of the following would be considered trace evidence in a fire investigation?

In a fire investigation, trace evidence refers to small amounts of material that can indicate the presence of ignitable liquids or other substances related to the fire's origin or development. Residue from ignitable liquids serves as critical trace evidence because it can help investigators determine if flammable materials were used to start or spread the fire. This type of evidence is particularly important for identifying potential arson or confirming the fire's cause.

Large pieces of debris, visible smoke, and fire logs do not fall into the category of trace evidence. Debris is generally categorized as physical evidence, while visible smoke is an observable phenomenon that indicates a fire's presence but does not provide specific details about its causes or contributing factors. A fire log is documentation of fire-related activity but does not provide the same level of forensic detail as trace evidence does. Thus, residues from ignitable liquids are essential for analysis in fire investigations, making them the correct choice for identifying trace evidence.