Question: The 2010 Pentagon shooting was an attack upon the headquarters of which U.S. department?
Sentence (from "The Pentagon"): The Pentagon is the headquarters of the United States Department of Defense, located in Arlington County, Virginia, across the Potomac River from Washington, D.C. As a symbol of the U.S. military, "The Pentagon" is often used metonymically to refer to the U.S. Department of Defense.
Relevant evidence: Yes