Which sentence contains an underlined restrictive clause?

the books that are stacked neatly on the top shelf belong to my great-grandfather.

the girl who broke the downstairs window with a baseball is knocking on the front door.

the store allowed the items that were purchased less than thirty days ago to be returned.

the restaurant, which had its grand opening two months ago, is always crowded.

Restrictive clauses are not offset by commas, therefore answer choice D is eliminated. Also, this type of clause functions as an adjective. 

In this case, the best answer is B. The restrictive clause is, "who broke the downstairs window with a baseball". That clause describes the girl, which identifies who the girl is. She's the girl who broke the window.

history teacher

Explanation:

the author was a lecturer

published 2003