think about the five categories of features that distinguish a useful, credible source. if you found a book…

think about the five categories of features that distinguish a useful, credible source. if you found a book that is unbiased, well - researched by an expert, and full of useful facts, but its twenty years out of date, which criterion is missing?\npurpose and perspective\naccuracy\nrelevance\nauthority\ntimeframe
Answer
Brief Explanations:
The book is described as unbiased (related to purpose and perspective), well - researched by an expert (authority), and full of useful facts (accuracy). However, it is twenty years out of date, indicating a lack of currency which is related to the timeframe criterion for a credible source.
Answer:
Timeframe