The correct answer is B) order of importance from most to least important.
The description of the organization of the excerpt from the Library of Congress is in order of importance from most to least important.
The source is "local history and genealogy reading room, Library of Congress, 8 mar. 2011. web. 1 aug 2011.
Almost all the libraries in the United States uses the classification of the U.S. Library of Congress or the Dewey system to organize books on the shelves. To arrange the books, the system uses letters and numbers. So the student ora n individual can look for the title in the catalog, search for it on the web, and then goes to the correct shelf an find the book