Final answer:
A dream would be considered spectral evidence. This type of subjective evidence was used during the Salem Witch Trials but is not considered reliable by modern legal standards.
Step-by-step explanation:
Spectral evidence is a form of evidence based on dreams and visions. It was used during the Salem Witch Trials in the 17th century. Out of the given options, a dream would be considered spectral evidence. This type of evidence is highly subjective and not based on physical or scientific proof, which makes it unreliable in the context of modern legal standards. Spectral evidence was one of the reasons why the witch trials were particularly notorious, as it allowed for convictions based on unverifiable personal experiences.