Final answer:
The denotation of the word 'conclusive' is that it refers to evidence that is impossible to disprove, signifying that the evidence establishes a fact with a high degree of certainty.
Step-by-step explanation:
The student asked what the denotation of the word 'conclusive' is, as used in the sentence 'The attorney claimed that the evidence was conclusive.' The denotation of 'conclusive' refers to option 2: impossible to disprove.
This means that the evidence is so strong and definitive that it cannot be called into question. In the context of law or science, 'conclusive' evidence is sufficient to establish a fact or prove a point to the extent that there are no reasonable doubts left. It typically leads to the closure of an argument or the end of a search for more evidence.