Magazine article: Sugar consumption may exacerbate attention deficit disorder (ADD) in children. A recent study found that children produce large amounts of adrenaline within hours after consuming large amounts of sugar. This increase in adrenaline is especially noticeable if the source of sugar is candy, in which case the sugar' s effects are not ameliorated by the ingestion of other foodstuffs. Which one of the following is an assumption on which the argument in the magazine article depends? ['Increased adrenaline production can make ADD more severe in children.', 'Sugar consumed with food substances other than candy does not substantially increase the level of adrenaline in the bloodstream of children with ADD.', 'The adrenaline level of children who do not have ADD is not increased by excessive sugar consumption.', 'The most effective way to treat ADD in children is to restrict their intake of sugars.']