The following question, consist of two words each that have a certain relationship to each other, followed by four lettered pairs of words. Select the lettered pair that has the same relationship as the original pair of words: Butter : Milk :: Book : ?

The answer is C. Chapter.

Butter is made from milk, and a chapter is a part of a book.

A. Author is the person who writes a book.
B. Printing is the process of making copies of a book.
D. Paper is the material that books are made of.

In the original pair, butter is a product of milk, and a chapter is a part of a book. In each of the other pairs, the first word is not a product of the second word.