Manufacturers are now required to make all cigarette lighters child-resistant by equipping them with safety levers. But this change is unlikely to result in a significant reduction in the number of fires caused by children playing with lighters, because children given the opportunity can figure out how to work the safety levers and__. Which of the following, if true, most logically completes the argument below? ['approximately 5, 000 fires per year have been attributed to children playing with lighters before the safety levers were required', 'unlike child-resistant lighters, lighters that are not child-resistant can be operated by children as young as two years old', 'many of the fires started by young children are quickly detected and extinguished by their parents', 'adults are more likely to leave child-resistant lighters than non-child-resistant lighters in places that are accessible to children']