You have a diary thought to be written by a confederate soldier during the Cival War. A handwriting expert believes the writing matches other samples that have already been traced to this man. A carbon-dating expert can verify the age of the document. The diary gives an account of a battle, but you have other documents that contradict some of the events as written. Based on this information, what should you question about the diary?

accuracy
validity
authenticity
ability to pass
a test of external criticism