Which of the following is TRUE about environmental tobacco smoke (ETS)?A. Between 1988 and 2008, detectable levels of nicotine exposure in nonsmokers decreased.B. As of 2016, all workplaces throughout the United States are required to be 100 percent smoke-free.C. Whereas mainstream smoke is the smoke exhaled by smokers, sidestream smoke is the smoke emitted from the end of a burning cigarette.D. ETS has far fewer carcinogens, tar, and nicotine than mainstream smoke.