You need to write an essay about hot air ballooning. You know you've seen a good book on this topic,

but you can't remember the name of the book or the name of the author. How could you most easily find

this book in the library?

A. Look under "balloons" in the Readers' Guide.

B. Locate the author card for the book in the card catalog.

C. Locate the subject card for the book in the card catalog.

D. Locate the title card for the book in the card catalog.