Sarah who works at the CD store is a sentence fragment?

You are absolutely correct! "Sarah who works at the CD store" is a sentence fragment.

Here's why:

* Missing a Verb: It lacks a main verb to tell us what Sarah does. For example, "Sarah who works at the CD store is friendly."

* Incomplete Thought: It doesn't convey a complete thought. We're left wondering what about Sarah?

To make it a complete sentence, you need to add a verb and finish the thought. For example:

* Sarah who works at the CD store loves helping customers find the perfect album.

* Sarah who works at the CD store is a music enthusiast.