A politician running for office writes a book about her major accomplishments and charitable donations. What problem might a historian have when trying to use this book as a source for a historical argument?
A. The book is likely to be biased in favor of the politician.
B. The book is a primary source and cannot be credible.
C. The book is about charity rather than important political themes.
D. The book is not old enough to be considered a reliable source.