Which sentence from the passage uses passive voice?

“Leaders of the world's governments have to make life-and-death decisions on a daily basis.” (paragraph 2)

“International espionage—or spying—is a messy and complex business that has been around for as long as there have been governments (about five thousand years).” (paragraph 4)

“A spy usually works through a person called a controller, who may offer training, provide assignments, and serve as the conduit for information.” (paragraph 6)

“Spies, however, aren't just in make-believe; every day in the real world, spies are watching, listening, taking pictures, and reporting their findings.” (paragraph 1)