Dolly must clean up her room before she goes out. 17. in this sentence, what word begins the subordinate clause?

- "the basic difference between keywords and subjects is that subjects (or "subject headings") have been predetermined, while keywords have not. a keyword is an easy place to start because you can use any word that seems to fit your search; this is called "natural language" searching."

c is the answer because first she would blush to make the reader wonder why which they find out in the next line.