A weapon of mass destruction is MOST accurately defined as: Select one:
a. any device used for the express purpose of creating carnage in an effort to make a particular point.
b. a device or agent used to destroy a specific area or region within a given geographic location.
c. a nuclear or chemical weapon that can be launched from one country to another country.
d. any agent used to bring about mass death, casualties, or massive infrastructural damage.

d. any agent used to bring about mass death, casualties, or massive infrastructural damage.

Explanation:

This is the definition that best describes what a weapon of mass destruction is. A weapon of mass destruction (WMD) is a type of weapon that brings about mass death, casualties or massive damage to human infrastructure, natural structures or the biosphere. The word is used more in a political sense than in a technical sense, as there is no universal agreement on what weapons would be considered WMD.