Suppose you have read two different books on world war ii, and each book has different arguments about how the war started. which of the following sources provides the best support for the authors' arguments?
a. an article claiming that world war ii was the most important war in history
b. a review of the two books written by a popular national newspaper columnist
c. a world war ii history website made by high school students for a final project
d. a set of diary entries written by generals who planned strategies during world war ii