3. Read the following paragraph from the article. . Back in 1996, David Blight, a professor of American History at Yale University, was researching a book on the Civil War when he had one of those once-in-a-career eureka moments. A curator at Harvard's Houghton Library asked if he wanted to look through two boxes of unsorted material from Union veterans. Which phrase from the article BEST emphasizes what the author means by "eureka moment"?

A. remarkable discovery

B. unsorted material

C. still amazed

D. entirely forgotten​