Which of the following resources would be most helpful for a writer who is trying to use a greater diversity of vocabulary in a written passage?

Question

Quizplus · Accepted Answer

A thesaurus is a book that lists words in groups of synonyms and related concepts.
Encyclopedia is incorrect. An encyclopedia is most useful for finding facts on a variety of subjects. 
Style guide is incorrect. A style guide is most useful for determining proper punctuation. It contains a set of standards for the writing and design of documents. 
Almanac is incorrect. An almanac is an annual calendar containing important dates and statistical information such as astronomical data and tide tables.

Which of the Following Resources Would Be Most Helpful for a Writer