During the War of 1812, the British set fire to the U.S. Capitol. They also burned the 3,000 books in the Library of Congress. Thomas Jefferson helped create the library when he was president. He chose books and hired the first two librarians. By the time the war started, he was retired. He had a library of books at his home. It was known as the finest private library in the country.
He offered to sell Congress his 6,487 books for $23,950. He hoped to build a new Library of Congress. Congress was excited to get the books for such a low price. His books covered many topics. The library once had books on only history or law. Jefferson's books covered art, science, and more. He also had books in French, Spanish, and Latin. He thought Congress should read about all subjects.

Which line best shows an idea that is important to include in a summary of this passage?
A.
By the time the war started, he was retired.
B.
He thought Congress should read about all subjects.
C.
He hoped to build a new Library of Congress.
D.
The library once had books on only history or law.